Safety Box ******* deduction off my Bank account.

Safety Box is deducting R56 a month out of my bank account unauthorised,this has been going on for a long time,I always saw the amount going off,but never worried about it(Is that how you do it,small amounts so that we do not pick it up) I do not know this company and has never spoken to them. Safety Box please explain to us how you manage to withdraw money out of my account without my approval.