Bank claims Gold Coast woman wasn't given $10 million just unlimited monthly spend cap on credit card

The Australian bank at the centre of a $10 million surprise deposit into a Gold Coast woman's bank account has said the money was never available to her and the result of an ATM glitch.

Sue Lamb of Labrador was yesterday stunned to find the massive windfall after withdrawing cash from an ATM and seeing "Available balance: $9,990,420" on her bank receipt.

Earlier today the 49-year-old manager of a small medical business said ANZ had removed the money from her business credit card account and left her with a debt of $7,500.

She believes the card should only have a debt of around $900.

An ANZ spokesman declined to provide specific details as to the reason why Ms Lamb was led to believe she was an instant millionaire.

"We would like to apologise to Ms Lamb for any inconvenience and we will be contacting her today," the she said.

"Due to customer confidentiality we are unable to go into detail on this situation, however we can confirm that the customer chose to have an unlimited 'monthly spend cap' on their account, which is common place for small business customers to manage their cash flow."

She said this did not however mean the customer could access "unlimited funds or outspend the account's credit limit".

"When the customer reaches their credit limit, they must then make a payment in order to allow them to further spend beyond the credit limit," she said.

"The available balance on the BOQ (Bank of Queensland) ATM receipt refers to the amount of the monthly spend cap (monthly spend cap less any spend from that month) rather than the available credit (total credit limit including debit or credit transactions for that month).

"We're investigating why the BOQ's receipt is showing the monthly spend cap rather than the actual balance."

Earlier today, Ms Lamb said had she phoned ANZ bank about the $10 million because she didn't want to get a visit from the police who may have thought she was planning to steal the money.

In 2011, New Zealand police arrested a man and his mother after they fled with $10 million which was deposited into their Westpac Bank account by mistake.

"I heard about these guys in NZ running off with $10 million so I knew I needed to call the bank but I couldn't believe they would not help me," Ms Lamb said.

"It's like something out of a movie and I just want it gone."

Asked what she would have done if she really did have $10 million, she said she would pay for herself and her friends to travel around the world on cruise ships.

"I would get the girls and just go cruising on the Queen Mary 2 about 20 times," she said.

"Then I would probably go to the beach."