Adding charges to account

The only package we have with telkom is a 10 meg fibre contract for R799 p.m. From July this year we have been getting charged for things other than this fibre package making our total due range from past R799 to R1200 upwards. We tried to resolve this at a telkom branch but were told it has to be done over the phone with the billing section. We then did this and after explaining our situation and giving all the relevant information we were told it would be pursued and resolved. This was done in September and it is now November and nothing has been fixed. It is already poor practice to wrongly put charges on an account but that coupled with the fact that it is not being fixed is just shocking. I really hope this is attended to as we are getting told we need to pay or our contract will be canceled. We entered into a 24 month contract agreement to pay only R799 p.m for 24 months and now this is happening . . . .