I've been trying for far to long

Sick and tired of explaining the same thing over and over to you people it's either you don't want to understand, or you clearly don't want to. In my previous complaint I said I don't do debt order and I pay cash monthly, yet you people persist and then charge me extra cause the debit didn't come through. I've spoken to the MTN, and your call center so tell me what I am to do???? for months now I pay extra penalty and why I don't know.