First, review your rental agreement: if it says you will pay for any damage incurred while the truck was in your care or possession, you are responsible for this despite fault. An agreement that someone will pay for any damage that occurs to a rental vehicle is legal and enforceable.If there as no such provision in the agreement you signed, they could only get the money from you if 1) you were at fault and 2) they sued you and won by proving your fault in court--without an agreement (e.g. in the rental agreement) that lets them simply charge your card, you can't do this. In this event, you could try to dispute the charge and the bank should allow your dispute if U-haul can't show some agreement allowing them to impose this charge on you. However, if you did dispute the charge, U-haul could still sue you if they feel you were at fault, and could get a court order for you to pay if they can show your fault in court.They could also refuse to rent to you again: any private business may refuse to rent to someone whom they believe (even incorrectly) cost it money and refused to reimburse  or pay.