If you overpay your AmEx amount due, leaving a negative balance, will AmEx send a check to you for the amount of the negative balance?

I prepaid a large amount on my AmEx so that I could charge more than the limit that AmEx set for me after a mini-financial review. My company's controller messed up; when it was time to pay the statement, instead of paying the prepayment amount to me and the rest to AmEx (which would have left a $0 balance), he paid the whole thing to AmEx, leaving a major negative balance.

If I call AmEx and request a check, will they do it? Will there be any negative consequences? The negative balance is huge- like the price of several new cars, a small house, etc.

Thanks!