you’re missing the point! It IS a big deal for a person wishing to apply for a Long term residence visa (LTR), a Thai Elite visa or a Destination Thailand visa (DTV). Because, if they have an overstay on their record their application for any of these visa’s will be denied.
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”.