I have one data point on this sort of thing:

Enterprise was paid a lot of money by my credit card insurer for a small ding (over $600). The insurer declined to pay the unsubstantiated loss of use charge ($100 or so) and the administrative fee.

Enterprise never wrote me again about it. I am guessing that they got enough money from the insurer for the damage (I thought the reimbursed amount was excessive), and that if total reimbursement=n*total requested, where n>0.75, they simply close the case.