Nedbank taking debit order without concent

I took out a personal loan with Nedbank months ago and paid by debit order out of my Nedbank current account. Not one payment was missed and I authorised the debit order to go off my current account on the 25th of every month. Begining of December I received a sms saying the pmt will be debited on the 15th alternatively reply with a sms back with a prefered date. Also start getting messages that my account is in arrears. Not one month since I took out the loan was not paid or in arrears. I rep**** asking for the 26th. Despite my reply they debited my current account on the 22nd and once again on the 28th. The call centre tell me they cannot reverse payments between Nedbank accounts. So please be aware of Nedbank they take your money without authorisation and despite paying every month on time according to the agreement. They clearly do what they want. I am changing my current account to another bank immediately and stuff Nedbank they will get EFT payments from now onwards. And this is how they treat Platinum account holders!