GoldCar Rental review: Credit card was charged when renting the car

The topic of our claim is: Goldcar mistake to have charged our credit card (instead of blocking) and therefore there is a EUR currency exchange difference. When Goldcar charged our credit card on 25.10.2019, the EUR currency at our bank was 4.9209 lei. When the deposit was refunded on 02.11.2019, the EUR currency at our bank was 4.5881 lei. This lead to a difference of 418. 79 lei in our bank account (approx 90 eur). We claim for Goldcar to refund this amount.
If the DEPOSIT would have been blocked on our credit card, as it is mentioned in the rental contract, we wouldn't have had this discrepancy.
contract no: [protected]