I rented a car and i brought it back with a dent, the guy in the car rental told me that i have CC insurance so i just have to fill out the form and do nothing, a few months later i receive a letter from Avis with a bill of $700 for the dent, i asked them what is the bill for, they told me that there was no claim made for the dent, i called up the CC company they said that they can't pay anymore since I'm more then 45 days since i returned my car, Avis says they are gonna give it to collection if i refuse to pay, do i have to worry about it?