Customers of the NAB were left temporarily out of pocket when a technical glitch resulted in double charging for some credit card transactions.
Some holders of the NAB Visa Debit cards were shocked this morning when they discovered that they had been billed more than once for transactions involving their cards.
NAB said the issue had been resolved before midday on Monday, but it was not before customers were left stranded with bills and at petrol stations.
Natalie Davis from Brisbane said that she had made a $700 payment on her credit card over the weekend, plus other small payments. When she logged into her account on Monday morning to pay the electricity bill she found the transactions had doubled, leaving her no money left to pay the bill.
She also said the direct debit health insurance payments from her account failed, and she was anxious about not being covered until she was able to make this month's payment.
One Facebook customer reported feeling embarrassed at a petrol station when she was unable to pay for petrol and get the kids to school. Another said her card was declined when she went to buy medicine for her son.
In an announcement on Twitter, the bank apologised for the glitch and said they were working to fix the problem as soon as possible. "We are working to resolve this issue as soon as possible so customers aren't left out of pocket."
Duplicated transactions should now be reversed in impacted accounts and account balances corrected. Again, we're very sorry! ^EA— NAB (@NAB) June 3, 2014
The bank provided a temporary fee-free overdraft facility for customers that needed immediate access to cash.
Customers would have started seeing cash back in their accounts from midday Tuesday and transaction histories will be updated Tuesday night.
In a statement an NAB spokesman also said that customers who had already experienced an overdraft would not be charged fees.
NAB customers, for their part, also took social media to vent their frustration.
Two days with no money thanks to #nab .. Finally fixed!!! We can eat now!— Rach Howard (@racheebaybee91) June 3, 2014
The news comes after the bank last week defended its multi-billion dollar effort to update its core technology systems under a project known as 'NextGen', a program that first got underway in 2007. Critics say the massive project has become unwieldy and hard to manage.
NAB group executive of enterprise services and transformation Lisa Gray said the scale of the project was unmatched by any bank in the world.
"For a program of this size and scale and complexity, it is where we would expect it to be," Ms Gray told Fairfax Media.
But her comments came only weeks after the bank revealed it would be forced to pay further refunds due to a glitch that occurred in 2012.
In 2012, the bank's wealth division paid out $1.9 million to 43,000 customers after it discovered an error that resulted in customers being allocated the wrong investment income into their accounts.
But last month it completed a review of the matter - relating to its Navigator platform - and identified the need to pay out around $200,000 more in compensation.
"These issues are largely around processes, systems and controls. We know there are improvements that need to be made and we have already started to make the necessary changes,'' NAB Wealth group executive Andrew Hagger said at the time.
But the latest NAB problems do not appear to be on the same scale as the massive systems meltdown that played havoc with customers in late 2010, when the bank suffered a two-week failure in its core banking system.
The problems left customer accounts inaccessible for days and NAB was forced to open branches outside normal hours to allow customers access to their money.
NAB has also not been the only bank beset by systems problems this year.
In January NAB’s rival ANZ announced it was conducting a sweeping review of all home loan, savings and small business accounts, after a major glitch forced it to refund $70 million to 235,000 home loan customers due to incorrect interest charges.
- with Chris Jenkins, Alexandra Back