Advantage of dealing with nationwide companies as opposed to mom & pop local companies. Small claim in city nearest to your home that has an office or agency of the company in question for purpose of recovering amounts you had to pay. Argue that the company should not win the case because it waited so long as to deprive you the right to insurance coverage. As well as argue that the company did not make a claim when (on return day) you could at least see that the damage was not caused by the person who rented after you.

Travel tips:
http://members.aol.com/ajaynejr/travel.htm