£500 Hertz deposit that somehow went ‘undetected’

It was supposed to be for a deposit which we were told would be refunded. But we can’t get it backI rented a car from Hertz at High Wycombe in June 2018. It took an imprint of my credit card for a £500 deposit that would be destroyed upon my return of the vehicle.At the end of the rental it advised me it would return the £500 once its card machine was up and operating. When it did not arrive, I was told they had a backlog of refunds they were getting through. After weeks of thi