Incompetence of Telkom agents

I had a 24 months contract with Telkom which ended 31st of Oct 2018 but for some reason I am still billed monthly payments. I went to cancelled at the branch was told to download an app inorder to be able to cancel which I did and cancelled to my suprise on the Nov month they deducted, I went to my bank reversed but they went to my account. I have now recieve a statement stating the amount owed for the month of Nov and Dec. Its an inconvenience on my side because I dont have time to go cancel something I had already cancelled.