I'm on Orange and I rarely have a problem with their phones or network and when I do need to call, like the other week 5 mins waiting just after lunch time and I got straight through. 5 mins later I was off the phone and chuffed
Sorry to hear your not getting on as well as you did with Orange, but whos better? 3? Vodafone? BTCellnet? and that other one ... is it Onetel?
Vodafone would be my only other choice.