Cancelled but still being charged

I gave notice in mid-September to cancel my fixed line with Telkom. My obligation is to give a full calendar month which I have done. I am therefore not liable from 1 November 2017.

Somehow, I continue to be billed despite numerous emails.

I don't know what I need to do to get someone to reverse the charge because I am not paying this amount. I pay what is owing but I WILL NOT pay a cent to Telkom that is not owing.

Someone needs to reverse this charge.