Poor service from Telkom

I have had terrible service from Telkom from the time I took out my ADSL contract in October 2017. My billing was never correct and I had to go into the store or call the call centre for them to log disputes to correct this. In July 2018 I app**** for a cancellation of my ADSL line. Since them I have followed up regarding the cancellation and they always cannot seem to find my application, and finally after going through all the times I have submitted and called in, they find the application which seems to have not been processed. In the mean time Telkom continues to charge me monthly. I am so frustrated with Telkom and there service. If you go into the store for assistance, they advised that they cannot help you and you need to call the call centre. If you call the call centre they cannot find your application. I currently do not know what more to do in order for my contract to be cancelled and to get some service from Telkom. I am so frustrated!