Michael, I can't help with your rather complicated scenario, but one thing I advise you to do today is to go into your bank account and CANCEL the DD to Sky - which should have been done in the first place, so your bank would have rejected those two months' claims for payment from Sky.
I wouldn't do any more of this negotiation over the phone, where you have no record of what's being said to you, and you probably never speak to the same person. Instead, do it by email, and keep the sent emails, or send by mail, next day signed for, so it's tracked all the way.