Well, you could always give Mav a call
Seriously though, I think the reason that people get away with things like this is the lack of accountability from all the people in the chain. As you've pointed out it's too easy for eBay and the like to just wash their hands of it.
As for the small claims court, well, it's alot of hassle to go through and if somebody is unscrupulous enough not to refund your money they may be equally defiant of the court. Also, the value of the claim may not justify all the hassle.
The last time I had anything like this it was a holiday advertised by a major travel company as a 'cruise and stay' holiday - 7 days cruising the Greek Islands on a small 40 passenger boat followed by a 7 day stay at a 5 star in Lindos, Rhodes. The whole thing was packaged as a top end luxury holiday and the boat was described so that you had visions of being under sail half the time and mooring up in a little cove to swim ashore for a barbeque. So when we pitched up in Rhodes harbour to find the boat was an old tub with communal areas that would make a run down 1960's transport cafe look plush, cabins that were made out of strawboard (and below deck when we had paid extra for a deck cabin). The engine ran all night even when moored, because the boat wasn't equipped with any type of 'umbilical cord' to plug into harbourside power and so ran the engine to keep the generator running and it filled this little rabbit hutch strawboard cabin with eye-watering diesel fumes. It was impossible to stay choking on diesel fumes so we went up into the communal area again to find all the crew sleeping on the bench seats in their string vests. Real luxury huh? Anyway, we only stayed there for one night and jumped ship for the 5 star hotel. Did I ever get any compensation? Nope...months of trying later the company tactics of dicking you around until you give up paid off.
I just wrote it down to experience and learned that instead of writing a cheque out to pay for the holiday it would've been cheap insurance to pay the 4% extra handling fee and to have paid by credit card.