Had a similar scam from sixt usa a few weeks after returning the car.
claimed scratches here n there but the car was fine when i returned it.
told them so n just ignored them.
total scam.

Another scam they pull is to charge for an extra day, claiming the car was returned past the assigned time.
this racks up another day of rental.

Rented from many car companies before and sixt is the only car rental place that scams like that.

Totally untrustworthy.
never renting from them again.
Terrible business