Discovery and Avis: deposit money for rental

Guys(Avis and Discovery Bank), you really need to review the relationship between you two.

Hired a car via my insurance in September and Avis told me that they needed R2000 deposit money. I used my Discovery debit card to make that payment and I was told by Avis employees where I picked up the car that they will reverse the money and it will be returned when I bring back the car and it may take up to 30 for the money to be returned.

Over a month has passed now upon following up with both companies, Avis sent me a letter saying they don’t have the money, and they sent me a letter to follow up with Discovery. Discovery says they also don’t have the money as they don’t withdraw it.

Now I'm wondering what this means?

Does it mean I took an Avi car without a Deposit?

What does it mean as I swiped my card and punched in my pin, surely there was some form of a transaction:

Where is the money? Where is the money?