Sixt blocked a huge deposit on my card, how can I make them release it faster?

Sixt says that the security hold should be released within 24 business hours after you return the car and pay for the hire. However, it may take your bank 3 to 10 business days to show that the funds are no longer blocked.

If the hold hasn't been lifted, you can call Sixt's customer service or go to a store and ask for a manual reversal. If 5 days have gone by, some regional Sixt offices will let you do this.

If the problem remains unresolved, consider filing a complaint on Xolvie to raise awareness about the issue and find support.