Even trying to cancel ADT contract is awful

Unbelievably poor communication from ADT again. I finally decided to move to a different service provider, and a signed cancellation form was emailed to ADT on 31 Oct. BUT they never acknowledged it and continued to bill me on 1 Dec (well after 30 days notice for cancellation), including their annual radio fee too, just to add insult to injury. Trying to unravel this, and getting them to refund me, has been a nightmare. Their "Customer Service Consultant" is never available, apart from one conversation when she promised to process the cancellation and refund me. Since then, emails are ignored and promises to call me back are not kept. So in the end I got my bank to revoke the debit order authority, and thus got my money back. I will have to keep emailing the bank monthly to do this, until ADT finally wakes up to the fact that they have lost (actually driven away) a customer of 20 years' standing.