Incorrect Billing

I am very disappointed with the extremely poor service I received from Telkom and their staff. I have been going back and forth since June trying to resolve the billing issue. Telkom is debiting me an amount we did not agree on and would sometimes debit random amounts. I have tried getting help from their customer service without luck. Tried getting help from the stores however it appears that the issue is with their head office. I was told that I should drive to the head office to complain, it's very shocking for a company of that magnitude to not have a complaints dept to handle issues like this. Telkom please do the right thing return what is due to me.