African bank-Call Centre agent bad attitude

I have a loan with African Bank, they debit me monthly on the 27th, this month (Dec 2015) I was debited on the 14th (today), I have no funds in my account, meaning my bank will now charge me for a debit order that has bounced. I called African bank spoke to Sphiwe Moloto at the collections department. She was rude! I gave her my story and asked her, why I was debited early? who did they confirm with to debit early? She said management called my employee to confirm salary date, I asked to speak to management, she said she didn't know who management was or how to get hold of them. Sphiwe Moloto **** about anyone calling employee - we are not paid yet, I have moved companies....the employee she claims have been called-their staff members are not paid yet as well. (I called to confirm). I would think that, I as the client should be called or texted to confirm salary dates over the Dec holidays. Creditors can not just debit without consent. I am not happy with this. I need an explanation.