I have used the long stay parking for the last 5 years and had no problem, This year i was offered an upgrade (a week before going) to park in the short stay for only £9.99, I took up the offer as I thought it would save time on my return (No waiting for bus transfer). I was sent a confirmation email. On returning I went to my car and drove to the exit only to find that my parking ticket came up as "blacklisted" and had to ring for help, After about 10 minutes waiting the call was answered, I explained the situation and was asked for my registration, After another 5 minutes the barrier was raised without any comunication, No sorry, Have a nice day, just nothing, I may as well have saved my £9.99 and got the bus to the long stay, Made a complaint via email (thought perhaps my £9.99 might be refunded as a gesture) but no just a reply saying that they had been having computer problems.