Once you're in - there's no getting out!!

I have been trying to cancel my contract with Damelin for just over a year now. After receiving terrible service (no student help, books that came in drips and draps over a 6 month period, books that have just never come at all) I decided to terminate the contract only to be asked to reconsider and rather place it "on hold" which I stupidly did. After a month or two I went ahead with the cancellation and I thought that was it.... that was last year. Now for the last few months they have been pestering me, trying to debit my account and saying that I need to pay for the months it was "cancelled" until they will officially cancel it ??? There's makes no sense to me and it is impossible to get hold of anyone there that is able to help me. My emails either bounce back or get ignored. The ones that are rep**** to are short, rude and completely unhelpful and to try and reach anyone over the phone is laughable. It seems my options are to either: A) cancel the debit order every month and just accept that that's just what we do now. OR B) pay an amount no one is able to give me for a period of time no one can disclose in the hopes that maybe next month I won't get a notification at 3am to say they've yet again debited my account!!!