RippedOff, I hear you, we all here you - no one is saying that billing you after cancellation is right, no one is saying that how you feel is wrong. Look at it this way - you have an end goal, getting your money back that you feel you were charged for after cancellation. Fine, I'm with you. The question now is how to accomplish that goal. There are a number of avenues you can take and some will cause you more trouble than others - even if they all get you to your intended destination.
If you do not pay, allow the bill to go overdue and then overdue beyond 30 Days you are going to have a hit on your credit report. Now you will have two things you need to deal with - getting your money back for the second month that you should not have been charged for AND fighting to get the 30-Day Late off your credit report. While it would not be "fair" that you were charged after cancellation and now have a ding on your credit report you still would have them. And these things are not going to be affecting AMEX, they will be affecting you. (it may affect AMEX if you win a case based on FCRA violations but you still will have to clean your credit report)
It's just logical - pay the bill, be 100% sure that you have indeed cancelled this time, get that cancellation in writing by mail, and then begin the process of getting your money refunded, FCRA violations and all.
I've just spent well over 6 months trying to get one 30 Day Late off my report - I just accomplished that a few days ago. Believe me, you do not want to go that route.
Work smart, not hard. Or at least smart AND hard 
Just here to help.
@Anonymous wrote:Providing a cancellation number, saying it was canceled, and continuing to bill isn't a scam? I know credit card lovers are in love with Amex, but if someone took $25 out of your wallet, you'd be calling the police no questions asked.
And you'd really let someone steal to protect your credit score? All you have to do is stand up for yourself. If you have proof of cancelation and they try to send you to collections for charges after that, you're going to win a boat load of money for FCRA violations.
Are you sure you really want that username for the long term? Ok.
