Frustration with Telkom

I submitted a cancellation letter to Telkom on the 8th of June to cancel all lines and internet services. I have had to submit the letter twice. I had a call from Telkom, querying the lines, and verbally told them as well about the cancellation. Each month I continue to receive accounts. I have paid these accounts but have not had any feedback with regards to the cancellation and the billing just continues.....