Went to pick up our yearly passes today only to no...

Went to pick up our yearly passes today only to not be allowed in afterwards as we hadn't pre-booked. In order to pre-book however you must have a pass number. Now I can pre-book. However there is no availability for two weeks and when I get as far as entering all my information and then bank details it just has a pop up box telling me to try again in 20 minutes which I have been doing on and off throughout the day.I even changed the devices I was trying to book with as I couldn't believe it was Chessingtons fault.
It is like a big wind up and I keep looking around to see if there is a camera on me waiting to see when I snap and eventually ask for the money back for the family's premium season passes. It won't be long Chessington I assure you! This is daylight robbery.
Really disappointed.