On this occasion when we returned from our holiday at 1.30am when we and several other cars approached the barriers to exit the car park, the card reading machines would not accept our cards and for us it requested that we pay over £80 for parking. We like the others who had pre-booked had to leave the cars and go into the office to have our cards revalidated but we also had to show our paperwork to prove we had already pre-booked and paid. After a long day of hanging around at hotels, airports all you want to do is go home not have trouble exiting a car park when you have already pre-paid.