If payment was made on a credit card I would call the issuer and see if there is some recourse. Ie, you were not provided with the advertised accommodations that you booked. I’ve successfully had cc charges reversed in the past.
you’re the foolish one! foolishness is not doing your due diligence on something as important as travel health insurance! AND I said, START with TrustPilot, “and go from here”.