Good luck w/ Amex. I've been dealing w/ something similar but nothing have dealt with only clueless replies (e.g., it was non-refundable so go pound sand on your chargeback). Is there a mailing address and/or contact for Amex CS/Dispute a bit higher up? Someone that understands that one should not have to pay for a service that was not provided (denied) even with the term non-refundable is the merchant's excuse.

Cheers