Avis is not refunding my deposit

I hired a vehicle from Avis for a period of 7 days from the 3rd to 9th February 2026 the total cost when I returned the vehicle was R18 248, 71 (no damage was found on the vehicle). This meant that Avis needs to refund me an amount of R 10 251,29, they had deducted R28 500,00 from my account. After a few days I phoned Avis and asked when I would be refunded. I was informed that this takes between 7 and 12 days. That time has long since lapsed and I am still waiting for my money to be returned. I find this totally unacceptable and am tired of listening to Avis excuses.