bad service, Incorrect billing

we had a landline with telkom, we tried to cancel the line in January but telkom retention department convinced us to change to prepaid. a while later we were informed that prepaid is no longer available for residential use. Telkom subsequently changed the package to another package without my consent. since the conversion the line has been dead and we have not used it. Telkom has continuously billed us even though the line is not working. we went to the telkom store in Cresta in Feb 2018 , in June 2018 and in July 2018 , a query was logged with them but nothing has happened. we also used the new online process to cancel the line but still nothing is being done and we are being billed. Our telkom account was never in arrears, in January 2018 after my request my account was up to date in fact it was paid in advance. we are now sitting with a bill in arrears for a service we have not asked for or used. please stop billing us and cancel the line with immediate effect. please check, this line never made or received calls since the conversion. telkom needs to reverse all the incorrect charges for the past few months. please stop billing me cancel the line and remove it from my name. thanks