Refund me back by today

My name is Amukelani. I have bond account with FNB and it happens that last month I skip one month installment and I made an arrangement to pay the whole a earies amount on the 31 January 2020. But to my surprise yesterday they have debit my account without my authorization. And phoned fnb homeloan and they told me that they cannot reverse it because account was not up to date. The fact that the arrangement was on place to settle the remaining earies amount is not important. I think FNB employees need to revisit the National Credit Act which states that you cannot debit client's account if there is arrangement in place. I need my money back to my account by today.