Even if the contract says that you are liable to pay the agreed sum, there are massive legal hurdles to overcome before the charity could enforce this. As previous posters have mentioned, they are effectively selling the place for starters. At the end of the day, ask yourself this: even if they are technically able to take you to court, are they ACTUALLY going to do so? No.
Who is going to stand in front of a small claims court and try to convince them that a genuinely injured runner (with evidence of their injury) has to pay up? Nobody, certainly not a charity with an image to protect. As someone has already said, threaten to tell the papers.
Bear in mind that the charity will probably do absolutely everything to convince you that they WILL go to court, but I think the likelihood is extremely remote. Stick to your guns and ignore the smokescreen.
The refusal of most races (with some notable exceptions like the Grizzly) to allow runners to transfer numbers. If I've paid £15+ to enter and can't run due to unforseen circumstances, I should be able to pass on my number rather than let it go to waste. The only reason many runners swap numbers 'illegally' so to speak is the greed and laziness of organisers who kid themselves they're getting an extra entry out of it. A simple swap system could be brought in for all races with little hassle
Had to allow myself a wry smile at the website's statement that online results will be 'slightly' delayed, which apparently means 'by the end of the week'. How the hell can it take a week to publish results?! Perhaps it was simply a badly worded message and meant by the end of THIS week, but even so....
Good race overall, but the t shirt situation was annoying even though it was unavoidable (race director locking his keys in the car apparently, something I've done before). I now have a massive one that will be lining the cat's basket.