Aucklander Chris Leggett, 30, checked his account balance on Sunday night and noticed the most recent transaction was an overseas ATM fee of $5.
He then saw $329 taken out that he couldn't explain so rang the National Bank. "They told me this money was taken out of Canada."
He'd been assured of getting a full refund but he's had to transfer money from his savings to cover his rent this week - problematic as he is moving to the United States next week.
"I've had to cancel my eftpos card so I'll probably not have use of that while I'm here."
He said it was a worry that it appeared people could not protect themselves.
"It's not like I did anything to render myself vulnerable ... I understand it's more of a problem in the southern hemisphere than in the north because they're rolling out ATMs that are equipped to handle it."