It's a big piss off. I think there maybe are only a couple of ways to handle it personally. Firstly I try not to get affected emotionally: that's just like hitting myself over the head when someone's been trying to poke my eye out. Not so easy perhaps, so the way I try to look at it is to see it as a roulette wheel. You choose to play and that, the hunt, has to be enjoyed for its own sake. Otherwise you just get too pissed off to want to bother. Sometimes it's good, sometimes it's crap. Hey ho. (That wouldn't stop me writing a review of the cancelled booking and calling her a time-wasting cunt. As someone has pointed out with Sasha, that may be no reflection on her abilities if you get through the door on another occasion, but when a prossie gets a reputation most sensible punters will put their chips elsewhere.)
The other thing, as you would in a casino, while recognising that you'll still lose out some of the time (due to unforeseeable cuntishness or circumstances) is to punt more wisely. Work out whether reviews are worth what they appear to be. Train your instincts. Have a 'booking routine' that balances time expended against likelihood of success.
For instance, a week or thereabouts ago I emailed two prossies and asked about availability for same day booking and suggested my preferred time and date. One got back to me in about 40minutes suggesting a firm time close to the one I'd suggested. The other, whose profile listed several cities, said I should let her know some dates and she would maybe see what she could do. In other words, put myself at her disposal if she could be bothered being in Edinburgh. You know which one I punted.
One last thing, to the chap that travelled thru to Edinburgh to see Cute Samantha. If it's any consolation, she was 'ok' but I wouldn't even travel across town to see her again. Probably said as much in my review and got slagged off for it. People addicted to roulette tell you how wonderful it is, but technically you can consistently make your money go further on stud poker.