If you suspect your card has been lost or stolen, report it right away.
After Hours Numbers:
Lost/Stolen Debit Card: (800) 791-2525
Lost/Stolen Credit Card: (800) 442-4757
If you receive a new card to replace the one that was reported lost or stolen, be sure to contact any merchants who charge your account on a monthly or subscriptions basis (such as newspaper subscriptions, gym memberships, etc) and give them your new card information to avoid authorization problems.