@moderator007
Point taken - thanks for setting me straight.
When I thought about it again, after reading your post, I realised that I only ever buy things from AliExpress, EBay or sites that let me use PayPal. The one thing they all have in common is access to a reasonable dispute resolution system with real teeth.
I’m fine with contacting a seller once to ask for a problem to be solved, and then starting a formal dispute if they get awkward about it. It only takes a few moments, and if the dispute doesn’t go completely my way (I have to pay return postage, for example), well, I tried and I leave it at that.
I wouldn’t buy from those sellers if I didn’t have those safeguards, because there’s no way I’d let myself in for twelve rounds with a seller who knew that they could just stall until I got fed up. As you say, that’s just not worth it.