I contacted the local office of the FBI and reported this case of attempted credit card theft. Please do the same. If enough people call, the FBI may prioritize its investigation. Until they are caught and jailed, you can expect to hear from the callers at least once a week, each time using a different number and screen ID so that you can't block them. Sometimes they leave a message saying your credit card interest rate is "about to expire" (mine is good until 2015) or that they can lower it to 6 percent (mine is already at 6 percent). If you respond, of course, they ask for your card number. If you ask them to stop calling, they say they will remove you from their list (they don't have any list; they call at random through a computer program). If you call them back, you sometimes get a message that the number is no longer in service and sometimes a long hold after which they hang up on you.