Saph, I'd recommend a letter of complaint to Parry, but I wouldn't except too much back in the way of a refund, or even an apology. I've managed to sort out a change of dates now, but would be happy to accept your invitation of a pint some other game!
Hope you manage to get something sorted. If ever there was an example to illustrate the need for a fan's liaison officer, then this is surely it.