Capitec Disturbing information

I have a loan with Capitec bank and every month I make payment, it's don't via naedo and sometimes they go into a day earlier, put my account in a minus. On top of all this I looked at my statement and the loan amount is not coming down. There is an amount of just over R400 that is not accounted for... Where is all this money going to.... This is unacceptable. I will take this matter to ombudsman, because this is a total *******. I'm sure there is lots of customers that are going through the same thing.