Useless service no one knows what they are doing

I was overpaid my salary some years ago and have been paying back the money monthly - for me this should be complete, I have been trying to contact Nedbank just to find out the balance but I have been sent in circles and been on the phone for over an hour each person transferring me to the next person, NDCRS is the department and I have an NBIB reference number. I have lost all patience now and will cancel my debit order. You can call me when you are ready actually help me.