If it is a credit card, have them stop it right now and they will decline all charges going forward. Have them try to alert the cops too! They will send you a form to fill out and have a Notery sign it. Ask them to fax it to you to speed up the process or else it goes out bulk mail it could take 10 days just to get the form. Then you send it back and they review the information and should credit your account in a couple of days.
If it is a debt card it could take up to 45 days!!!