I think I would contact guns on pegs and let them know what's gone on, if you found the shoot through there website they need to be made aware of the situation and get the others you have found to do the same it will make your claims seem more genuine.
Post the shoot name as a rip off on as many forums as you can as often as you can be bothered over the next few years. this will cost them money in the long run.
Good luck getting your money back