Avis, I want my money Back ASAP

On 1 June I received a rental car from Avis. I swiped R3350 for the deposit and it was taken off my available balance. I returned the car on 3 June in East London. A few days later I recived a text from Avis stating that I need to settle the invoice amount of R522.08. I contacted Avis and told the lady that I had already paid a deposit, so Avis needs to deduct the R522.08 from the deposit and refund me the balance. On the 19th, I received a text from my bank stating that another R 3350 was deducted from my account by Avis...I have queried this and I am told that Avis does not have the money. Does this mean that the money is floating around in space? I have proof that 2 x R 3350 have been deducted and my available balances decreased. I did my part by paying the deposit, filling the car up wth fuel when I returned it and I kept it in a good condition, but now it is a huge struggle to receive my refund and the extra R3350 back from Avis.