He said he then tried to contact RBC customer service, but had been on hold for 25 minutes when he called us.
Several other customers claim their accounts were mysteriously overdrawn by thousands of dollars.
"I was trying to do the whole automated system. It's saying my card's declined. I got paid yesterday, so that's not possible. I go to the ATM, I'm $8,000 in the red," said RBC customer Rob Maiers.
Eyewitness News contacted RBC for an explanation and was told a computer error was to blame.
RBC CEO Scott Custer said a vendor that helps process debit and credit card purchases sent the bank a bad electronic file.
"If they did a debit card transaction last night, that transaction malfunctioned in the system and their accounts were overdrawn this morning by mistake," he explained.
Custer said his staff along with the vendor worked all night and morning to correct the problem. By 10:30 a.m. Friday, every single account was back to normal. Customers will not be responsible for any overdraft fees.
Customers told Eyewitness News that in this down economy, the experience left them more worried than it normally might have.
"I kinda thought that maybe the banks were closing down," said Maiers.
But Custer said there's no reason to worry.
"RBC was the most profitable bank in North America in 2008 - one of the strongest most stable financial companies in the world," he said. "Don't let a processing error by one of our vendors give you concern about the safety and soundness of RBC."