I returned the car as is and no refund

I was involved in an accident and my insurance included car rental. I went to avis to get the car and filled in all their forms and made the R2500 deposit for the car using their contactless method. I then returned the car with a full tank of petrol on the 22nd of April without a scratch. I was then informed the refund would take 7 to 20 working days. It has now been more than a month and i am yet to hear anything from them. I have reached out to them and received an escalation ref number but nothing has come of it. They are also not replying on any of the emails that was sent.