Incorrect billing and ITC listing

Three months ago I called telkom and asked that they change my debit order banking details because im no longer using the one they have. The agent confirmed that they changed them. On the day they had to debit they didnt debit. I had to pay the account via eft. I have been doing that for the past 3 months. This month I put money in my old account and telkom debited it. I reversed it because i have been paying via eft all these time. I called telkom and they said the agent didnt change the banking details. Now telkom sends me messages that i owe them. When i reuest a statement they send me a statement belonging to someone else, this is also against poppi act because someone’s information was sent to me. Over and above all that telkom now has listed me on the credit bureau for an amount I have been paying via eft because their agent didn't do as they had to