Their customer service is pretty responsive. I was able to get them to match a better sign-up bonus for my BCE that I read about on these forums.
Use the message service on their website, and write a compelling letter. Kiss a little amex butt, tell them how great the card is, and that you made a tiny little mistake, and you're hoping the great customer service you've always heard about can make things right for you.
They'll get back to you, one way or another, in 24 hours.