Banking customers complained of being charged overdraw fees of up to $15 as they were unable to transfer money between accounts, while others claimed they were unable to make their rent payments.
But according to finance experts, if you’ve been charged a late fee due to the outage, you’re likely entitled to a refund.
"If you've been charged a late fee for something obviously out of your control, like a bank outage, contact your provider and request a refund,” Finder personal finance expert Taylor Blackburn told Yahoo Finance.
"Even if the outage was for a small window of time your bank may be lenient – especially if you have a good payment history and can make a case you tried to pay.”
He said the best way to challenge a late payment fee is to either call up your bank or use the online customer service line.
"In most instances, when it is a known issue like a power outage, your bank will be reasonable,” he said.
"If your bank refuses to help when you've done nothing wrong, you can always search for a better bank that pays you more interest and is more understanding."
He also suggested Australians set up autopayments for a few days in advance of the deadline. That way if the payment can’t be completed, the bank will nearly certainly reprocess the payment without a fee.
“In some cases you can even get perks or discounts for setting up a direct debit,” Blackburn said.
"As soon as you realise there is an issue, or potential issue, contact your bank and document dates and times."