The DVLA insist that photos showing the car contravening the "rules" is held by the parking operator. Failure to have these photos is a breach of their contract with the DVLA. So check that they actually have them. In addition the photos must be unequivocal - they must show the car, the car park and the signs. Here are examples of correct and incorrect photo evidence. Not having photos or having incorrect photos means it is unlikely any court claim will succeed. So check them.