Deductions made without permission given

I need the amount that was deducted from my bank account on the 15th December 2018 to be refunded urgently. I have an arrangement in place with FNB and that amount was already deducted. Collab deducted money from my bank account without my permission and this is not the first time this has happened. I want my money to be refunded urgently as you had no right do this.