Car rental deposit still not refunded

Dear Avis Customer Service,

I rented a car from Avis in Durban on 31 August, paying the rental fee and deposit with my card. I returned the car the same day and have since followed up on my deposit refund. Avis confirmed on 12 September that the deposit was refunded and accepted by my bank, yet as of today, 17 September, the amount still hasn't appeared in my account.

As someone who rarely hires cars and chose Avis over E-hailing services, this experience has been disappointing. How difficult can it be to make refund?

I look forward to your prompt resolution.

Best regards, Dakalo