Well, I think that if you give them more than 24 (or it MIGHT be 48) hours notice, then it's no problem. However, if you do NOT, then they are not legally bound to give you your money OR another
test. That is my understanding anyway. Don't worry about them being rude. Some people will just be rude regardless of circumstances. However, I WOULD be concerned that perhaps you did not give enough notice before cancelling the exam. As I said they may not be required to refund or give another exam. If that is the case, I thik you just have to accept the circumstances.
Matt