Unauthorised debit orders from Avis Potch

Rented a car out in September at the Potchefstroom branch and swiped my debit card there and at the end of the lease l renewed for a month then all of a sudden unauthorised debit orders from Avis started tapping into my bank acc and messing it up and upon returning the car l realised the information on my invoice was not mine, from home address to id number..although l returned the car their systems still say l have the car whilst they take money out of my account without me authorising it...