Can someone tell me where I can get redress for this totally unfair conduct toward me on the part of MBD?

MBD just sent me a message saying that someone tried to call me from their call center, but was unable to reach me. They then continued to say that my avoiding their phone calls will negatively affect my credit rating. I didn't avoid their call. In fact, I answered the call, and they dropped the line, or there was a network error. So I would like to ask if there is not an ombudsperson I can talk to about MBD's shocking conduct? I have received phone calls telling me to pay my credit card, but I am paying it through Finwell Legal, which they themselves admit to knowing. When I raised this on a phone call I received, they said, yes they know. So I asked why they are phoning me. Then they said it was to remind me to make payments. I pointed out that they should also know that I have a debit order in place, so why would they need to remind me? Then I recalled that on the statement they sent me, they are charging me R5.00 for the SMS's they send me. SMS's, like the phone call, telling me to make payments, when I am already working with Finwell on a debit order basis to pay my account.

Can someone explain why I need to be charged for unnecessary SMS's and then get threats for allegedly not answering unnecessary phone calls? To me, this seems like a total abuse of power, and I will not stand for it. Can someone tell me where I can get redress for this totally unfair conduct toward me on the part of MBD?