TD Canada Trust has taken out full-page ads in newspapers across to country to apologize for a major computer glitch on Saturday which left thousands of its customers without cash and banking services.

Services such as bank machines and telephone banking were out for 12 hours. Grocery stores, restaurants and other retailers were forced to turn away confused customers whose debit cards wouldn't work.

"We're sorry about the inconvenience you may have experienced," reads a line in the advertisement.

The bank, which services about 13 million customers, says the shutdown was caused by "a rare and isolated hardware problem" in its computer system.

Customers were advised to go to local bank branches that were open, to obtain cash. However, even if the branches were open for business, customers had to contend with enormous lineups. Some branches reportedly closed early for the day.

"No one was getting any money, and everyone was leaving pretty mad," one customer told CFTO News in Toronto.

TD has been known as TD Canada Trust since a 1999 merger that saw Canada Trust bought by TD Bank for $8 billion.