Cancelled service, still getting billed?!

I emailed through all forms for Telkom to cancel my phone line and Internet on 19 June 2017, cancellation date requested was 30 July 2017. I checked on 31 July and the services were not working and were disconnected. Imagine my surprise when I still get an August 2017 bill from Telkom even though the service has been disconnected. I called Telkom on 11 July 2017and spoke to Portia Bruint to explain the problem, I emailed her the cancellation forms I had sent through. She said she would feedback to me but never did. Pls look into dispute # ********** 5 and sort this out as the August bill needs to be reversed as service no longer exists!