Need advice- Amazon refunded buyer $4500 despite signed delivery

Hey everyone, I’m dealing with a frustrating situation as an Amazon seller and could use some advice. I sold a $4500 item on Amazon, and the buyer received it with signature confirmation under their full name. Everything seemed fine at first.

The original delivery deadline was Thursday, but the buyer wasn’t home, so UPS redirected it to a local Access Point. He picked it up on Friday and signed for it there. The tracking clearly shows it was delivered and signed for.

Two weeks later, I randomly get an email saying Amazon refunded the buyer due to “unable to deliver”—which makes no sense because it was delivered and signed for.

I opened a T-Claim with Amazon explaining everything, showed proof of delivery and signature, and it still got denied.

Now I’m out $4500, the buyer has the item and the money, and Amazon isn’t helping. I’m wondering if the missed Thursday delivery deadline played a role(which I had zero control of) even though the package was picked up the next day.

Has anyone dealt with something similar or have any suggestions on what I can do next? Appreciate any help.