Nedbank is failing to honour their contract

I am so angry with BAD POOR SERVICE that Nedbank is giving to their customers. I have personal loan with them of which I am paying but so disappointed with they way this bank has been treating me. I made it clear even on my contract that they can not deduct money before the 26th of every month unless that date falls on weekend. From November 2015 Nedbank fail to do what is right, they went into my account to deduct the money on the 25th. What makes me more angrier is one of their consultant when I called querying this he/she just said is not an issue because they got the money they wanted. You people can't even see the wrong thing you have done by not honoring your contract what kind of creditors are you? It's companies like you who put many customers in bad credit record. I am so ****ed off by calling you people with one and same thing every two weeks. I have agreement with Nedbank to go into my account on the 26th of every month not before that except date falls on weekend. what I don't understand is what is so difficult for YOU PEOPLE to get that into your thick skull. YOUR SERVICE IS BAD IT\S STINK IN SUCH A WAY I CAN NOT EVEN RECOMMEND YOU TO ANY ONE. ANGRYYY"