Cell C Holding my Service Ransom!!!!

Been trying to cancel my Cell C Fibre which i have had for 2 years - they **** to me about the offer I would be getting initially and have been over charging me for the last 12 months by adding extra sim cards to my account which i never requested or received - I have made many many requests to give 30 days notice on my account but haven't even received an automated response to say thank you for my query nothing what so ever - my new provider cannot take over until they confirm the cancellation - what are you doing Mr Douglas Craigie Stevenson the CEO - Cant imagine that you are a very busy man as i don't see any work being done at Cell C other than ripping clients off and providing an extremely shoddy service - i have now approached the Ombudsman who will be investigating the case further - I'm going to cancel my debit order then lets see how quickly you contact me - pathetic they will never get another cent from me