Supersonic?? More like Supershady!!!

Endless frustration with Supersonic. We inherited Supersonic - we originally signed with Nepic. After struggling for months with these guys - we tried to cancel our line to move to a more efficient service provider. Many phonecalls and frustrations later, our line was still not released. We gave up, and decided to just keep going with Supersonic. Well - this has clearly messed with everything, debit orders go through sporadically - some months it works, some months not. We ended up paying in a huge amount (for us) to have our account cleared and reactivated. 3 days later they debited the same amount from my account, and told me to have the bank reverse it , which I did. Now, my statement shows a zero balance owing but my line is suspended. What does it take to have an internet connection that actually works and a regular debit order of the agreed amount go through every month????? Beyond annoyed. As I type this I am on hold, again, for the umpteenth time.. so far it's been 20 mins. I just don't know what to do anymore. Can't get my line released, but can't get internet access through Supersonic either.