ROTTEN NEDBANK. YOU NEED TO DO BETTER

I app**** for a loan a few months ago and when asked specified for the debit order date on the 25th monthly. The account has been running without a hitch and each payment has been met. Nedbank has in the meantime decided to change that debit order date without speaking to the customer. No questions or permissions. If I had not been paying my account I would understand but they have never had to call me for a payment. It goes off by debit order successfully. How can they decide to just debit MY account at will when they decide without my permission. This is my account and does not say in partnership with NEDBANK. I spoke to Angelo Muller who very rudely told me that there is no manager to speak to or team leader because they in a meeting. I WANT ANSWERS. THIS IS MY ACCOUNT NOT OURS