you didnt say anything when it happened? If you didnt you are basically screwed. Because now they are going to ask you to prove that they did it..and since you left already thats going to be difficult. Now if you said something and they failed to do so you can attempt to sue them. But its honestly going to cost you more to sue then you will get out of it. Now I don't know canadas laws regarding litigation so you may or may not get reimbursed for court fees and I dont know how they go about small claims court. But Your next problem is "usually" there is a disclaimer before you go through that it is your responsibility to secure loose items on the car..I.E-antennas, windshildwipers etc...So you may not even have a case.