So disappointed in Telkom Service

In a nutshell, I faxed through cancellation of my landline and adsl service on the 22nd Nov 2017 effective the 31st Dec 2017. Telkom then went on to bill me for Service Fees etc for January 2018 which I disputed. I have been in constant contact with them since January and to date have not had finalization. I unplugged this line on the 26th Dec 2017 so feel that I might have made some calls which will be payable from the 21 - 26 December. They keep charging interest every month on the "arrears" for January and every month promise to sort it out. According to one of the consultants that I spoke to she advised me that in actual fact if they reverse the fees for January they would actually owe me R57 odd Rand. I have spoken nicely to them, I have fought with them, I have raised my voice and sworn at them, I have laughed and cried and just don't know what more to do. Who can help me?