In which case they'd find themselves sued if they pulled that on me, and that's the approach everyone should take to that kind of customer hostility.

Small claims courts / magistrate court filings are cheap pretty much everywhere, and does not require a lawyer. But it would tie up some exec and someone at their law firm for enough time that it'd be a loss for them whether they in or lose.

And in the EU at least they'd also face a near guaranteed loss in most countries if they tried to punish a customer for taking advantage of their rights to return a product that did not work as advertised.