Had a cancelled Tlv-Nyc flight from AA that was booked via Amex travel. Been trying to get a refund from AA for months but been getting nowhere. They claim it’s a year since the booking happened the ticket expired. I finally got a email from AA that they agree that I deserve a refund but they can’t verify the payment method, so I should contact the booking agency. When I had Amex contact AA the refund was denied again. Any advice how to escalate or other help?