National Australia Bank has taken an extraordinary step to "make things right" with its customers, paying for full-page newspaper ads to apologise for last weekend's outage.
The bank is starting to pay back the thousands of business customers that were left out of pocket on Saturday when their entire system went down.
Businesses have been claiming they're owed anything from a few hundred dollars to more than A$10,000 ($10,853).
For a little under six hours, a "technical glitch" stopped any NAB customers from using its ATMs, mobile app and EFTPOS machines.
In a hand-signed article from the bank's CEO Andrew Thorburn, the company said it was "truly sorry" for the outage and that on Saturday, it "failed" to get the fundamentals right.
Mark, a machinery business owner from Cessnock, NSW told 2GB he made one phone call and was almost immediately reimbursed for the A$1000 in lost business.
"I called them on Monday morning when I got to work. They asked a lot of questions … and about two or three hours later I had another phone call back from some manager higher up in the bank and we had a discussion about what possible business had we lost and what profits I would have lost because I didn't sell those goods, and he made me an offer," Mark told the radio station.
"I very quickly gave him a bank account number to put the money in before he changed his mind," he added.
On Saturday, Craig Daniell, co-owner of Melbourne's Kingfisher Seafoods told News Corp the outage would cost him a fair slice of profit.
"We've had easily 100 customers who couldn't buy their produce this morning," he said.
"There's been quite a few angry customers; it's been a massive inconvenience."
Daniell said most customers use cards to pay for their produce.
"It's impacted us big time, 80 per cent of our sales are on card now … out here in Camberwell they don't use cash," he said.
"Saturday is our busiest day, you rely on Saturday sales to balance out the rest of the week.
"My wife is very upset, when you pay a lot of fees to the bank it gets very frustrating."
A NAB spokesman was unable to confirm the exact number of business owners who were out of pocket from Saturday's outage or the exact amount of money the bank would have to pay.
The spokesman did, however, say the bank was in the process of refund everyone with a legitimate claim.
NAB is already in the process of repaying customers and is encouraging anyone who might've lost out on Saturday to contact the bank.
Yesterday, the bank's business executive general manager Cindy Batchelor said they would look to refund customers who were put out by the glitch.
"If there was a loss that was driven by the outage today, then compensation will be provided to customers," she said.
"We'll work with each and every one of them to understand exactly what happened to that particular customer."
Almost immediately after the system went down, one of the bank's chief executives Anthony Healy posted an apology on Twitter.
"On behalf of the executive team and everyone here at NAB, I want to apologise for the outages that you were experiencing this morning with your banking services.
"I want to apologise to those who were out trying to do their shopping on a Saturday morning and particularly our merchants who are trying to do business and maintain banking services for their customers. We're sorry and it's not good enough," he said.
Dozens of customers lashed out at the bank on social media after they tweeted a separate apology, claiming they'd lost thousands in the outage.
"We just saw A$2500 walk out the door. But 'Sorry this happened on a Saturday' makes me feel all warm and fuzzy inside," one Twitter user replied.
Another wrote: "Sorry ain't good enough. You guys are making billions of dollars each year while us small businesses are losing money because customers are unable to pay for their groceries. Will we be getting compensated???"