Avis ******* refusing to refund my money

I had a reservation for a car to be collected at King Shaka Airport on 28 December 2021.

On arrival at the airport, The vehicle I had booked was not available, I had one credit card as per normal. I couldn’t get the car as booked and had to make other means of travel. The next day I called your customer care line as advised by the person assisting me on the desk, I was told that a refund will be requested and paid into my account. No money paid yet.