So. Managed to get to the Orange shop and I think I came out on top. I've got a shiny new phone, unlimited 8Mb broadband and more talktime and texts then I could shake a stick at for about 2quid less than I used to pay.
I do unfortunately have a new number. As soon as I work out what it is I'll let people know. The old phone is still active as best as it can be with a dodgy radio.