unpaid debit

I received sms regarding all my debit orders from the bank in November. I only became aware that my FNB policy was unpaid when FNB sent me an sms to notify me of such. I then visited Nedbank to request a statement from which it appeared that there were sufficient funds for my policy to deduct. I then called the Nedbank call centre for explanation. I was only told the obvious, that is, there were insufficient funds which is something I was disputing. I then requested them to give me their complaints department's contacts. I logged a complaint telephonically and I was given ***. I waited but in vein until I decided to call them myself. The person who dealt with my complaint promised to send the matter to their IT department and give me a call the following day. I have been waiting for the call for weeks. I called them again today only to tell me a story that no ordinary human being can understand. In my entire experience both as a banker and a customer I have never experienced this lack of professionalism, lack of urgency when dealing with a complaint. Worse of all they all give me an unhealthy attitude as if I am insane or stupid.