Telkom's Speed Charge and the Great *******

After cancelling my ADSL line with Telkom 3 months ago, and just keeping my landline, I noticed that they are charging me R200 for speed every month. This is not right! When I discussed this with a very unhelpful agent I was told that I need to forward proof of my cancellation so that they can see I cancelled the speed? We have fibre, who needs speed on a landline? The agent certainly could not explain this to me. Telkom never explained this to me when I cancelled ADSL. Certainly I expect a full credit for the time they have been charging me for a service I have not used since cancelling.