Amex Travel Flight Cancelation Error

I booked a flight a couple days ago on Amex Travel but I'm unable to make it anymore. I paid extra to book one that's fully refundable before April 5 (flight is on the 6th) but after booking, both the cancelation button and cancelation policies button promoted me an unknown error. This is the same on desktop and mobile.

I tried chatting with the Amex team over 2 days and they just kept redirecting me outside of the chat. I tried calling the Travel team but they were either experiencing high call volumes or are not working, even when the Amex agent from the chat claimed the Travel team was working. No one has been able to resolve a system error that will eventually cost me over 1000 pounds.

This is so disappointing. Does anyone know what I should do?