Exactly. I was thinking about this too, and while I'm no lawyer, I wouldn't be surprised if a judge were to throw the whole thing out, saying there is actually No agreement. (In which case you wouldn't be held to anything.) This even assumes that they would bother with any legal proceedings on what, a $100, maybe $200 purchase? As unhinged as the staff may be, the organization's own lawyers would tell them it was a waste of time.
Bottom line is, they accepted your money, and handed you a snake.
Done deal.