dont no if this is too late bensorhero but moonay left of this bit of info.
"Calls to the 0871 number are charged at 10p./minute from a BT landline. Calls from other networks and mobiles may vary. "
its not cheep to talk to them if your call is a long one. plus theres a £2 booking charge if you buy a ticket.
just to give you the fulest info thats all.