Insurance company denying claim due to revoked license?

I am asking this on behalf of my mother, who is elderly and doesn’t use a computer. My mother lives in Alabama, and her car was struck from behind on 2/4/15 and sustained significant damage to the back end. A police report was taken at the scene and insurance information was exchanged.

It was later determined that the driver of the vehicle at fault was not the owner of the insured vehicle, and he was driving on a revoked drivers license. He claimed he had permission to drive the insured’s vehicle.

The insurance company sent out an inspector and although they never would provide my mother with a report from the inspection, my mother had a reputable body shop inspect her car and they believed the cost to repair her vehicle would be around $4,300.

After 30 days and numerous telephone calls to the insurance company’s adjuster without any response, my mother was finally told that her claim was denied because the driver was driving on a revoked drivers license.

The adjuster stated twice that their insured had given him permission to drive the vehicle, but because his license was revoked and he was not the owner of the insured vehicle, that that gave the insurance company grounds to deny the claim.

Is this legal?

My mother has State Farm Insurance and carries collision insurance on her vehicle, however, her deductible is $1,000 and she does not have uninsured motorist coverage.

Also, her vehicle is not safe to drive as the bumper is very loose and the tail lights are not functional, all due to the accident.

This accident has created stress and and financial hardship on my mother and I would like to help her resolve it the best way possible. What can we do? Thank you.