Enterprise Rent a Car Fradulent Damage Morristown New Jersey

I rented a Hyundai Elantra at Enterprise Rent a Car in Morristown NJ on June 2 2013 because my car was totaled and my insurance company paid for a rental through Enterprise.   When I examined the car there were several black smudges above the rear right wheel well.   The rental agent told me not to worry about it - it didnt need to be noted.

When I returned the car on June 13 the agent examined the smudge, and running her hand over it claimed there was a dent in the same spot as the smudge.   The dent was not visible to the eye, it was about 2 inches long and barely noticeable to the touch.   I stated that it must have been casued by whatever caused the smudge and that it was preexisting - but since a dent wasn't noted on the contract (just a smudge) I needed to be accountable for it.

The negotiation that followed proved to me this was a fraud.   The agent acted concerned about what would happen to my insurance rates if it was reported and asked what my deductable was.  I said $500 but said I wasnt going to pay $500 for a negligable dent that I didn't cause.   She quickly agreed to "split the difference" and charge me $250.   I paid the $250 to just have it done with.  

But that wasnt the end.   Enterprise then sent me an accident report to fill out to provide my insurance information for them to make a claim. 

I understand from other sources that Enterprise agents are paid an incentive to "find" damage on cars so they can charge for it.  Any advice on how to fight this, or further places where I can report this fraud, would be appreciated.