Hi,
I empathize with your situation and sincerely hope it is brought to an end very soon. It really is a nightmare dealling with these people. It is like a weight on your shoulders you just want to unburden.
I have spoken with several lawyers and each of them says that in their personal opinion Supanet are corrupt in selling a 12 or 18 month contract over the telephone and (without warning or notice) at the same time actually tying you into a 24 month contract (£39.99 charge).
If I had more time I would write to OFCOM or the Offices of Fair Trading to try and get this company looked into further.
Hope it goes well.