AmEx should have just given you a new account. I've had my account with them since 1988.
Last year I was using my Citi credit card to pay for all my son's college applications. About a month later Citi sent me a text of suspicious activity and I called them and they had 3 charges that morning all around one school that my son had applied to. They froze the account denied the charges and sent me a new card Fed Ex.
I figured some starving college student had hacked the school system and grabbed my account info. The charges were all at fast food places near the school.
Be courteous to all, but intimate with few; and let those few be well tried before you give them your confidence. -George Washington