Poor Service

Poor service from Avis. I rented a car last month via my Insurance and the car was returned on the 4th of August 2021 then I was told the money I paid as deposit refundable will be paid back into my bank account within 10 working days till to date nothing was paid. Just today when I called their customer service they now then explain to me that they don't know what happened and they will communicate with their bank to be paid back within 48hrs.