ABSA has to explain DEBITING MY ACCOUNT without my consent

Today, 25 of February 2020, Absa has debited an amount of R 3 508.48 under reference "JOURNAL DEBIT RCCS BOS J" without my permission. I know this purely because I have called the general enquiries and spoke to a lady named Prudence who has adviced that this amount has been debited by the loans department.

I have a few questions regarding this : 1) How does Absa debit my account with my consent or even a conversation or an agreement on the amount that will be debited?

2) Who decides on a figure to deduct on someones else's account and who then implements it.

3) Is it even legal for banking institutes to self debit funds out of their customers accounts? Where does Absa get the power to debit whatever amount they wish to debit out of my account without consulting with me?

The ideal resolution : I would like my money back as well as a solid explanation as to who took the discussion to debt my account, who came up with figure to debit and who implemented this without my consent?

The worse part is that I have been calling the loans department on ***and every time i get the a consultant, the call is cut.

I need this money back ASAP accompanied with answers as to who this has happened.