Sixt The Hague Still Holding €418 Deposit 35 Days After Car Returned in Perfect Condition

I rented an SUV from the Sixt branch in The Hague, Netherlands, and a €418 deposit was charged to my credit card at the time of rental. I picked up the car on December 2nd and returned it in perfect condition on December 7th — yet approximately 35 days later, my deposit still has not been refunded.
Despite reaching out multiple times by email, every response I receive is the same automated, AI-generated reply with no real information, no clear explanation, and no meaningful update on where things stand. This has been both financially damaging and a deeply trust-breaking experience.
I am demanding that my €418 deposit be returned to me without further delay. After everything I have been through, I want it known that I will never use Sixt again and will not be recommending them to anyone around me.