If you want a quick way out of the contract why not adopt another approach, instead of you terminating the agreement try a bit of reverse psychology and get them to terminate it.
Try maxxing out the connection, leave it downloading permanently and see if you can breach the AUP terms and the cap
Or alternatively utilise your web space and host some illegal MP3s.
Or give them a call and hint you have uncapped your modem.
Maybe even cancel the direct debit, withold payment then move.
