[Pollster1]

what i was saying stores use to have signs saying we can refuse service to anyone.i don’t know about planes

With or without a sign, any business should have an almost unlimited right to refuse service. We then have an almost unlimited right to boycott that business if we disapprove.

[CaptainK]

With or without a sign, any business should have an almost unlimited right to refuse service.

But once they take your money and have it in their hands they should provide the service. It's too late to refuse the service when the check has already been cashed.