Unthorized debit amount

I have been renting a car with sani Sixt for 9 months.

I went to change a car and they gave me a car with a with a tyre pucnture. I went back the following morning to complain , they said they don’t have another car. I then waited and told them that im not going to change the tyre because i don’t want to be charged service fee as they have always charged me. I continue with the car just putting air on it , after insisting they got another car, for my surprise they went to my account debited service fee without even calling me.