I was with Supanet for many years, initially through dial up and then broadband. When I moved house 2 years ago they completely cocked up the account move. They said I had to cancel the account and reactivate at the new address. Only thing was, they activated the old dial up account and email address and cancelled the broadband completely. I was without internet for over 6 weeks and spent over 4 hours in total on the phone to them trying to sort out the mess. They did offer me the dial up account back as a temporary move, but having dial up was difficult at my new address initially. I was supposed to get the 8mb package with free evening & weekend calls for £11.99/month, but after a while (actually it was nearly a year!) I noticed I wasn't getting the call package, even though i was paying an extra £2 a month for the service. I rang them and they apologised (didn't refund me though) connected it but then emailed to say they were upping the price to £17.99 per month! I rang back to ask for a cheaper package and they said nope, so I went elsewhere. When I asked for my MAC code they were awkward, slow and gave me a whole load of bull, and asked why I was moving providers. When I said it was mainly because of price, but also customer service they said they could have done me a cheaper deal (oh now you say!) - too late by then, I had already signed up elsewhere.
They then sent me a letter to say return their modem within 10 days or pay £10 for it. (I had been away for a week so by the time I saw the letter I think I only just snuck in by the skin of my teeth with that!)
They tried to charge me for calls three weeks after I had moved providers and I eventually managed to get the account sorted, but they really do not know their backides from their elbows.
Their accounts department are terrible, and their overseas call centre sucks. They don't seem to have the right information available and although their technical knowledge is good, facts regarding accounts are sadly lacking.