We have pre-booked with NCP before and not a problem, buton our recent trip to Belfast we done the same pre-booked the car park, when we arrived at the barrier it didn't recognize my van reg plate so i called for assistance and we were told just take a ticket. Went off on our trip, but when we came back and put our ticket in the machine at the barrier to go out it said we owed 144 pounds so i called for assistance again and explained to them we had already pre-booked, and they said they would lift the barrier so got back in van were we sat waiting but nothing. 3 times they said they were going to lift the barrier but they never until i told them i would call the police as i was in need of my insulin, and would sue if they didn't let me out, and all of a sudden they lifted the barrier. I have never been so badly treated and who ever was on duty that night needs reprimanding. I think they were having a good laugh at my expense not impressed at all and wouldn't use again.