Unless you were going to proceed down some route of taking legal action against the hotel / restaurant / chair manufacturer, you're not apt to get much more. Add the challenge of the international nature of this, and it's more complicated than necessary.

You might be able to make your case on damages, but it will cost much more than what you've done to date (including legal fees).

While 80,000 Marriott Bonvoy points isn't that much, I think it's about as much as you an expect for an informal resolution.

I'm not a lawyer but these are my humble two cents.