I paid £115 for parking in short stay 2. Received the confirmation email to say it was all booked and paid for. Came back from holiday arrived about 2am, got to the car, got to the ticket barriers, put the ticket in and it said we owed about £160 or more can't remember the exact amount and had not recognised that it had been paid. I can't understand how that can happen it's supposed to be number plate Recognition? So pressed the button for assistance, spoke to someone on the other end who after asking us some questions saw it had indeed been paid beforehand and raised the barrier for us. This has happened to us twice before, once it hadn't read the number plate properly and had 1 number or letter wrong so had to get that sorted another time when I had to go find someone as the button I was pressing nobody was answering. So that is 3 times that has happened to us and all in all the parking service really needs improving especially the license number plate recognition and also to automatically recognising when parking has been pre paid. The Airport itself is wonderful, cannot fault it.