Alister Robbie had been regularly going over his 60GB data allowance, often paying Internode $30 extra on top of his monthly $69.95 broadband plan to buy additional data blocks.
Last year the Melbourne film editor checked Internode's website and found he could for some time have been getting 150GB for the same price. He says he's "pretty annoyed" the telco never told him about the new deal.
"It's annoying when you find out you could be saving all this money each month and because I'm interacting with the company each month to buy the data blocks you'd think it'd come up on their radar," said Robbie, 35.
Robin Hutcheon, 84, has been on the same iPrimus plan since 2008, paying up to $105 a month for his phone and internet package with a 2GB data allowance. When he called the telco two weeks ago he found out he could be paying half the price for a new plan with more than twice the included value.
"It's the first I'd heard about that new deal; I would've been on to it earlier if I had known," said Hutcheon, from Edgecliff in Sydney.
Consumers are being advised to take a moment during the holidays to check their internet and mobile plans where they could potentially save hundreds of dollars just by switching to a newer plan from their current provider or a competitor.
Telcos and internet service providers often update their plans throughout the year but existing customers, particularly those who are less tech-savvy or time poor, may not realise they could be paying less or getting much more for the same price.
And telcos may not exactly be beating down your door to tell you.
"Telcos and internet service providers rely on the fact that most of us think it's too hard to change to another provider, so once they have got your business, they stop competing for it," said Alan Kirkland, chief executive of consumer group Choice.
"This means that you can often be paying much more on your monthly bill than what your telco is offering to newer customers."
Kirkland said consumers could save hundreds of dollars a year simply by ringing their provider and asking to switch to a better plan.
He advised people to take a moment during the summer holidays to surf the web and check out the plans on offer. Those on a contract should make a note of when it is due to end and make sure they look for the best plan on offer then rather just rolling over the existing contract.
Elise Davidson, spokeswoman with the Australian Communications Consumer Action Network (ACCAN) said customers sometimes see great deals being offered by their existing provider but when they call up to ask about it are told it's only for new customers.
"Providers are under no obligation to tell you about cheaper or better value plans, although the good ones will," Davidson.
"You should be rewarded for your loyalty, but often it's customers who have been with the same provider for a long time who are getting the worst deal."
ACCAN's National Consumer Perceptions Survey, published in September, revealed that many Australians are reluctant to switch providers with almost a third of respondents saying they had never switched telecommunications providers and almost half had stayed with their provider for five years or more.
The survey found respondents aged 55 years and over were significantly more likely to have never changed service providers.
"People are actively trying to save money on other utilities like energy, but when it comes to telecommunications services many people just stay with the same provider, there is a real inertia in the market," said Davidson.
"Your provider isn't necessarily going to tell you when a cheaper or more plan becomes available so the onus is on the customer to check out new plans once contracts are up, rather than just staying on the same plan."
Telco analyst Paul Budde said with customers under contract telcos legally don't have to offer them new deals and the reason they don't is largely because of a lack of competition. He said sometimes a couple of months before the contract expires telcos will offer existing customers a better deal but only if they start another two-year contract.
"Because of a lack of real competition they can get away with not offering the new deal to existing customers," said Budde.
He said that the problem should be reduced with the NBN as since it is an open, wholesale-only network with better margins for service providers, the market would "move to a more utilities based infrastructure with competition concentrating on services and customer service".
A Telstra spokesman said if any customers wanted to change their plan or talk about their options they could contact the telco or visit their nearest Telstra store.
"We'll be happy to work with them and make sure they're on the right plan for their usage," he said. "We also regularly contact customers on older plans offering to move them to newer in-market plans that may better suit their usage."
An Optus spokesman said: "We actively look to inform our customers about new Optus plans and services through a number of channels, including direct mail, in-store customer service, our online store and more."
iiNet, which also owns Internode, said its customer service department will always suggest appropriate plans when customers call but would not switch customers to new plans without their involvement.
Vodafone said: "While we do not contact every customer when a new plan is released, customers are able to contact us to upgrade or change."