Exorbitant fees by Telkom.

I have had enough of paying exorbitant fees generated out of the sky from Telkom. I paid R950 2 months back for a charge that made no sense whatsoever, now I have a bill of R830 that was sent as a letter of demand over and above the amount of R422 I pay per month for my contract. I have had enough of Telkom to be honest. If these fees are not paid, they go onto my credit record and tarnish my name.

Is there any way to stop this?