Hertz Car Rental Overcharges For 3cm Scratch

I regret renting a car from Hertz for my trip abroad. The requested fees are exorbitant. To start off, I chose to go with the suggested damage insurance when making my reservation and made the payment accordingly. Upon returning the car, a minor scratch measuring 3 cm on the rear bumper caught their attention, resulting in an additional charge of approximately 340 euros. It's just a minor scratch, and I can back it up with a photo. When I rented through Economybooking, I paid 350 euros, but the deduction is not reflected on the invoice. There are a number of charges on the invoice that are difficult to understand. When renting through the website, the cost appeared to be around ₺12-13,000. Nevertheless, following these occurrences, the rental fee reached ₺30,000. When I attempted to clarify my circumstances at Hannover Airport, their response was simply that they were unable to assist. I'm curious about the insurance I bought and the reason behind the 340 euro charge for a small scratch. It's difficult to understand.