Poor customer service experience!!!!

I rented a car with AVIS 22nd December 2020 and my account was debited for R5930 on return of the car my account was yet debited again for R6400 on the 23rd of January 2021. It's now the 5th of March 2021 and I have not received my refund for the original amount, which they claim was a deposit. This is really frustrating. Poor customer service.!!!!!