Cancellation of Service

23 Jan 2015 Went to Telkom shop to cancel my account. Nobody the told me that it needs to be in writing. 23 May 2015 I call Telkom call center to cancel the service on my account. 9 Jan 2016 Went to Telkom shop again after my account line got cancelled and my account handed over due to no payment. Lady at Telkom told me she cant help me I need to phone the call center again and that I should not pay anything in the mean while. 12 Jan 2016 Phoned them but they don't understand the problem and cant put me through to somebody in charge who can. Debt collectors also phoned me and said I must pay the outstanding balance which has gone up from 614.81 to 928.90. I also got an email with the latest account of over 1200 rand. They keep billing me for a service I don't use anymore and have cut my line. How do I get them to cancel my account???