Avis not returning car hire deposit

I have hired a vw polo on the 15 December 2017 and return the car on the 18 December 2017 at Avis - Makhado banch.

It is almost 2 month now and I still have not received my deposit back from Avis.

My Details: Name : Nyiko , ID NO: ********** 689080

Cell : ********** 393