After an invoice of 1600 euros

After an invoice of 1600 euros

I rented a car from luxauto for the holiday for 16 days. I didn't get it as clean as it should be.
When it was returned, it was claimed that everything was ok inside, but it wasn't clean from the outside (I have a video), a little bit of dust and a little dirt next to the wheel.
I think it's a real shame to ask 15 euros for this after a bill of 1600 euros. I've been renting cars from other rentals for the summer, it's clear that it has to be clean but to be charged for dust on the outside???????