Help with Disputing Agoda Booking

Hello,

I recently booked a hotel through Agoda, but when I went to the property, I found out that the fitness room that was advertised was not there. I asked the property for a refund and of course they said no, so I just decided to find another hotel and dispute it later.

Well now that it came time for disputing, my dispute got denied. Agoda provided their terms and conditions and said that they did not provide any guarantees about the property and what not, and that I would have to raise my issues with the hotel. Obviously, the hotel has no reason to provide me with a refund, and AMEX is also unwilling to resolve the dispute in my favor.

What else can I do?