I'll have to ring the local CAB tomorrow. I'm not expecting anything, I'll probably end up having to stump up the cash for a new one myself despite it being someone else's mistake.
I'm just not sure what the law is in this instance. If it's any additional help to anyone that knows about this type of stuff, our energy supplier (EON) have said they'll send me a letter outlining exactly who was to blame and why, and they'll back me up in the event of needing to claim.