Bad credit score Nedbank to blame

Nedbank is a good bank but when it comes to the home loan date they do just what they want. I Now have a bad Credit score because of them. Tried to phone them a hundred times to rectify the issue and spent more than 2 hours on the phone without resolve just to get transferd and transferd . My home loan is to go off on the end of the month 30/31 In Aug it went off on the 31'st but now they say I missed a payment but it did go off on the 31 of Aug and today it went off without an notice on 29 Sep The best of all is that I'm a Business account holder.?????