But here's what is perhaps most important to do: Call the three national credit reporting organizations immediately to place a fraud alert on your name and SS#. The alert means any company that checks your credit knows your information was stolen and they have to contact you by phone to authorize new credit.
http://www.pvmirror.com/shouldknow/creditcard.html

Lost Credit Card Alert... If your traveler's credit cards are lost or stolen, one toll-free call, anytime of the day or night, puts our staff in motion to assist you. We will notify the credit card companies that the cards have been lost or stolen and order replacement cards immediately
http://www.tpionline.com/rescenter/res_center_main_tpi.htm

A poza tym możesz wystosować:
Notice of Lost Credit Card
Notice to Bank to Stop Payment of a Check
I dopiero później możesz kartę "cancel"

when my wallet was stolen last month i had phone all my credit card company to put a stop on my cards and wait for the replacement cards. tak sie to mowi przynajmniej w UK.