FNB Home Loans

I have a home loan with FNB, on my application I indicated that I wanted my debit to be on the 15th but I was advised that the first debit will be done on the last day of August then it will change back to the15 in September. I have called them on numerous occasions and submitted the necessary paper work as requested. As per usual, there has been no response and there just does not seem to be anybody with handles my matter.