A few years ago I ordered something off eBay. It was overpriced, but it was the only place selling this particular variant of the item. Anyway, the next day they sent me a message saying that variant was out of stock and could send me another instead, but of course I opted to cancel. After a lot of back and forth (them offering me dodgy extras and me refusing) they sent it anyway and told me to return it.
To cut a long story short, they did indeed send the item, but not me. And the mad part is, PayPal admitted to not caring, even with written proof from Royal Mail that the order wasn't addressed to me, PayPal pretty much said (I cant find the original dispute now, so not verbatim) that as long as the order was sent to someone, I have nothing to complain about.
In the end I just asked my bank for a chargeback, which took 5 minutes compared to the literal month the above took.