Thanks for the reply mate.
Hmm it looks like I need to call the bt number 0800 800 030.
I'm wondering what are others paying for the upto 80Mbps package? Apparently if I can compare what others are paying I might be able to get some discounts.
Personally, I would find TalkTalk, EE, etc. and their latest offers, give BT a ring and say you're leaving because they're cheaper.
With the new switching system, BT never initiate the cancellation, the new provider initiates does, so they can either say no and nothing will happen or - hopefully - they'll give you a great deal. Persistence is key.