Seems to happen to me every few months. More with Amex than others for some reason. I have like 6 Amex accounts between business and personal.

Amex normally just changes the last 4 numbers on the card. They told me next time they will issue totally new account numbers.

The last time they agreed to keep my business platinum card on for another 8 hours as I told them where it was going to be used. It was not perfect but worked. They will get a new card to you the next day wherever you are.