Whoopsadaisy! Citigroup has accidentally been charging many customers more than what they owe for months, with some of them not even realizing it was going on until the bank sent out a notification.
Cit's bill-pay app for iPads was the culprit in many cases, charging customers twice what they owed for bills or mortgage payments.
The New York Times says the bug started in the iPad app around July but wasn't detected until December, after consumers' complaints about payments being off.
Other mobile applications and the online bill payment system weren't affected, says Citi.