Check your Europcar bills for inappropriate add-ons

Been a loyal customer for 6 years. Received a bill after a 2 day rental of a Kia Picanto with 35 000km on the clock. Added to my bill was R350 of Valet cleaning! Never smoked, eat or drink on the car. Single driver with no passengers. On enquiry, they responded "It is noted that all seats and all carpets of the vehicle required valeting". Serously, why should I be responsible for the bill on cleaning the seats and carpets?