Several years ago this happened to the card clearing house where our company account was as well as my personal account. Our bank was very much on top of the situation and notified all customers as well as issuing new cards to all. A friend who worked at the bank and was anticipating retirement stayed on to work through verifying that all accounts were correctly handled and no unauthorized charges allowed. It was a major headache for her but she did a fantastic job of going through all the paperwork to be sure everything was done correctly.