“Insurance companies can deny a claim for any number of reasons.
As part of their coverage investigation, the other driver’s carrier would have obtained a copy of the rental car contract. If they have already sent you a formal written denial, they do not believe that they are contractually obligated to pay for your damages under their insured’s policy.
You can ask them who they believe to be responsible.
Contact the rental car company and determine their stance on the claim. If the car was rented for business purposes by a company, there may be another insurance company involved as well.
If you have collision coverage
on your policy, you should file a claim through your own insurance and let your carrier pursue the other party for the damages.”