Avis unauthorize debiting my account. Poor communication within the company

Avis did an unauthorized deduction from my account 2 weeks after returning the vehicle. The communication within the company is poor. I returned the vehicle on the 5th of Nov 2024; on the 11th of Nov 2024 I was contacted requesting the return of the already returned vehicle and on the system i returned it on the 7th of Nov. I had to prepay for the vehicle which i did but returned 5 days earlier. Instead of me being refunded the 5 days; an amount of R10460 was deducted from my account on the 18th of November 2024. I have requested an investigation and refund asap; but still no answers. I have been calling and emailing yet still no response. Ref nr: ***