Being billed on the wrong date

I am so fed up with Nedbank, I have asked them to debit my account on the 20th of every month but yet this is still not done. My credit record is also *****ed on ITC because someone at Nedbank didn't do their job properly. I can't asking for the same thing over and over. My account has to be debited on the 20th of every month. I think this has to be escalated to the ombudsman because no one is really listening to me. I also want my credit record to be cleared and I want proof of that A.S.A.P.