Billing error

I have an account with telkom and I am being debited an amount we did not agree on firstly on the first month I was billed an amount of R1750 of which I paid and the second month I was billed R887 I called to find out why am I being billed so much were else my contract states I have to pay R667 and still I am not getting answers I called to query and and I was given the run around with no certain answers and on my third month of billing I was billed R3000 did a reversal and Called them back to find out and still the same useless answers and they can't even transfer your queries to management so I want to find what is happening before they list me ... because if I don't get the answers I am taking this to the ombudsman and lawyers media and everything u can think of to make sure that you do right by your clients ....