3 deposits not returned!!!!!

I have had 3 deposits that have not been returned to me since the 13 October 2018. These three amounts total to R12 835!!!! No one from Avis seems to even care let alone answer any of my emails. I would advise never to use Avis as I am now forced to take it further. Very disappointing service and I am very upset about how much money they have ****** from me!!!!!