The damage has been to both little and big government. Coalition ministers and backbenchers have still not grasped how robo-debt has hurt their brand. Centrelink staff know all too well but who, above them at least, is paying the slightest attention?

Campbell might, in her cups, claim she was ambushed between relentless bipartisan pressure to cut her staff (Labor is as much to blame for this as the Coalition) and the Coalition's obsession with the idea that a high proportion of people on any form of welfare are scroungers, receiving benefits to which they are not morally – perhaps not legally – entitled.

But in fierce loyalty to ministers she has denied any staffing pressures – and implicitly any need for her agency to go unready into the robo-debt system as a way of making up for staff losses. It was the department, not the minister, that decided it was ready, when it was not. It was the department that decided to implement a deeply flawed computer program with processes completely at odds with public service values of welfare delivery.

Ministers do not get down to that level of administration. They rely on their departments. Public service leaders of the calibre the community has a right to expect – especially given their $700,000-plus salaries – should have resisted the pressures until the system was ready. Campbell's real problem is she put pleasing ministers ahead of duty to the public, the public interest and public service values.

Though the government has yet to appreciate the full size of the disaster – and some ministers are still trying to defend it – it is clear that the whole affair has severely damaged the reputation of the public service generally. In addition to the burden of endless waits in telephone queues making customers testy, cranky and uncooperative, will be the reinforcement of the notion that a public servant is a citizen's enemy, and will treat you as one.

The problem of welfare fraud that the government seemed to think the scheme is addressing was not in payments to chronic welfare recipients. It was to people who earned extra incomes during a year in which they received welfare benefits. Ordinary people essentially using the system properly, such as those who lost jobs, accessed unemployment benefits for a while and then found work. A good many other people facing accusations of indebtedness have been lower-income families accessing family tax benefits.

The basic problems with the system Centrelink put in place have been well rehearsed. The Tax Office has been at pains to point out that the fault lies with Human Services, not Tax. In effect, apples (annual incomes) were being compared with oranges (fortnightly) and, often, quite erroneous conclusions drawn. In many cases, the problem is not with the facts clients provided but with the inferences Centrelink, or now a computer, drew from them.

Hundreds of thousands of people were told they had been overpaid, and invited, with menaces, to "engage" with Centrelink to discuss their parlous situation with. In line with a culture pioneered by the Immigration Department, the clients were treated not as citizens with rights, but as people to be regarded as guilty until proven innocent, and with all of the onus of establishing no overpayment seeming to rest with them. Those who didn't receive their letter (perhaps because they had changed addresses after ceasing to be Centrelink dependents), those who could not understand it, and those who failed to respond with alacrity were treated as guilty, the debt regarded as established, and the client able to be harassed by private debt collectors. Some of these, no doubt on a percentage incentive, have used methods or made threats that, as witnesses to the Senate have pointed out, are probably illegal under Australian credit laws.

The adverse publicity has now probably made many of those wrongly accused of receiving overpayments aware of their rights. It is by no means clear that only a fifth of those accused, as the government suggests, were innocent of overpayment. Those are the ones who can readily establish themselves as victims of a very dodgy algorithm. Many others will not have the records or the capacity to gainsay the agency's assertions, will lack capable advocates or the capacity to counter interpretations of entitlement legislation, or cute departmental pretences that its record represents the complete truth, as known to Centrelink, and that if it is wrong, or deficient, then that is because the client has mis-advised it, or failed to inform it of "correct" facts.

My advice to any person against whom a debt has been raised is that they lodge a legal appeal, and have the onus of proof put on the agency. At the very least this will ensure that the claim is reviewed by an administrative lawyer. It is simply not good enough to claim, as Campbell has, that "people have always been responsible for providing the department with correct information", with the implication that if Centrelink, or the computer algorithm, had made a false deduction from the material, it must be the client's fault.

My second piece of advice is that any recipient of a letter seek advice and help from the electoral office of their local MP, especially if she or he is of the Coalition. Most electoral officers are very helpful, and even better at providing feedback to their boss than a direct letter to the MP.

In her evidence to the Senate, Campbell has gone beyond the call of duty in personally attaching herself with both the actions and the political rationales behind the scheme. Perhaps she thinks that schemes to hound welfare cheats are politically popular, and that even Labor governments (one of which appointed her) have been keen on the idea that much money can be saved by relentless suspicion of the poor. It seems unlikely this loyalty will be, or should be, rewarded.

It is probably unlikely the federal police will take any action against Human Service's self-serving notion that the Social Security Administration Act entitles it to breach a person's privacy if public complaints are made which the department believes to be unfounded. The legislation permits limited release of private information "for the purpose of administering the act", and it is drawing a long bow to claim this purpose includes protecting the agency from criticism, even unfair criticism, or in maintaining confidence in agency management or reputation.

The AFP, in its federal functions, is not a proper police in that many of its powers depend on referrals from agencies, rather than its own initiative. It has never demonstrated any zeal whatever in any matter where the actions of the government of the day might be criticised. One cannot quite say this of the DPP, but its practical insistence that any brief be watertight prevents its being a factor in law enforcement in such matters.

It is somewhat amazing that the Auditor-General's office has yet to seize the opportunity to examine the reliability of the department's algorithms, reversals of the onus of proof, use of bluster and menaces, and general disdain for the rights of Australians. But this failure fits with the general modern tendency of watchdogs to not bark very loudly, or at appropriate moments. Public interventions from the Commonwealth Ombudsman, Colin Neave, have been restricted to advice, issued in January, that anyone with a problem with Centrelink ring Centrelink itself, or perhaps a welfare rights organisation.

The Privacy Commissioner, Tim Pilgrim, has publicly raised his eyebrows at departmental interpretations of its "right" to breach the privacy of public complainants, but could hardly be said to have allayed public concerns, or to have assured everyone that the system has real checks and balances.

It's a curious thing that Campbell seems a good deal more relaxed about protecting the privacy of Centrelink's enemies and clients than she is about her own.

In another guise, she is a brigadier in the Army Reserve (in command of the Fifth Reserve Brigade). She was, at least until her recent public humiliations, regarded as a top candidate for the position of Defence Department secretary, when Dennis Richardson gruffly but falsely claims senectitude later this year. Campbell has said she is a better departmental secretary for being simultaneously a brigadier, and vice versa. Some, however, might suggest it has been a command culture, from her army rather than her public service background, that has brought her down.

On Thursday, I asked Defence public relations for details of Campbell's successive military appointments and ranks, if only for passing comment about her background. I knew it, broadly, if only from old departmental marketing handouts pushing her barrow, but I wanted a complete recent list, not merely highlights. The army refused me the information on privacy grounds. This is even though all senior officer appointments are gazetted, and, as such a matter of public record, though it would take ages to track it down. And even though army public relations has, at various times, published information glorifying her during some of her appointments, including a recent stint in Iraq.

It is information of a sort once routinely available of senior defence officers, in much the same way that one could, and did, regularly obtain the curriculum vitae (and photographs) of senior executive service-level public servants. (There was a day, too, when each and every one of these, and all officers of star rank, had their phone number listed in the Commonwealth Directory.)

The army could not, or would not, say when the new rule was invented, or why it was, but, whether designed to protect privacy or not, it is not required or suggested by the Privacy Act. The change may well have been under the reign of the present Chief of Army, General Angus Campbell (no relation), who has long been deeply antipathetic to anything other than press stenography. He's the one who invented the "on-water" rationale to prevent any public scrutiny and accountability for the Operation Sovereign Borders program of refusing refuge to and repelling persecuted people exercising their rights to seek asylum in Australia.

I asked for an explanation able to be attributed to Campbell for why his service was so gun-shy with information about its senior commanders. I received no answer. The director of army communications, Rebecca Constance, told me that no such information could be provided by Defence about anyone – even of a person of full general rank – without the permission of the officer herself or himself. Asked why, she required me to submit questions in writing. No answers were supplied before my deadline.

Defence PR suggested I contact the brigadier herself but, alas, Human Services, however anxious to volunteer information about clients, failed to answer both a written request and repeated phone messages to its departmental public relations person, who seemed unable to live up to a recorded promise of a quick call back. Nor did Campbell respond to a message on her mobile phone.

Indeed, it was like waiting for an answer to a call to Centrelink.

Actually, it would be hard, even for the army, to beat the privacy protections with which everyone in the Department of Human Services seems to be clothed. No risk of a debt collector calling anyone, from the secretary down. Neither the phone book, nor the internet record a switchboard number for the department, though the department's page in the phone book is replete with 1800 and other numbers for any number of Centrelink, Medicare, Child Support and other services.

One might even find someone from these agencies if you can stand the average 15-minute delay one will encounter if one does not hang up in sheer frustration. It says a lot about the department, its service culture and its broad approach to its clients that this 15-minute figure is regarded, complacently, as comfortably inside the department's aim of having the average delay being no more than 16 minutes. That's not counting the 4,118,686 hang-ups, non-connections, and phones going dead after a promised transfer to someone who might be able to answer the question, if you again wait indefinitely, hopefully more no more than 16 minutes.

When Centrelink was established, under the blessed Sue Vardon 20 years ago, it set new standards in efficient, effective, empathetic and accountable client-focused management. It is time that government responded to the fact that it has been slowly changing into an inhuman machine, a monster, a computer. We do not need it to have the artillery, armoured units, Sovereign Border cannon fodder or infantry otherwise under Campbell's command and control.

Jack Waterford is a former Canberra Times editor.