Auto Insurance Claims: state farm, volvo dealers, bumper covers

Question
hi i have full coverge insurnace with state farm in chicago illinois  my car was in accident my foult  now they will pay for the damages on my car  but only to use aftermaket parts can i do something to make them pay for orginal volvo parts they say i can use orginl parts but i have to pay the diference between aftermarket and  orginal volvo parts  .dont they have to repair the car as it was before the accident  to same condition with orignal volvo parts and the car will loose value with aftermaket parts   if you can tell what to do or to say that can help please do so ?
? thank you  

Answer
Enes.  
The laws and procedures regarding aftermarket parts vary from policy to policy and state to state.  Your policy must conform with state laws and insurance commissioner regulations.  What does your policy say about aftermarket parts?  There, you will find the answer to the first question.

Now as this is a Volvo, I'd be interested in knowing which parts are in question.  You see, I'm unfamiliar with any aftermarket crash parts that are even available for a Volvo with the exception of plastic bumper covers and lamps.  No one makes an aftermarket door, fender etc.  As far as mechanical parts, the ones that are available aftermarket such as radiators, condensers, some electrical components, wheels, brake parts, batteries, wiper blades, tires and glass are also parts that Volvo never actually manufactured to start with.  This is the case with most car companies.  All of those parts are sold by Volvo dealers at inflated prices and the boxes do say Volvo, but they are actually made by the same companies that produce the those parts for auto makers around the world and are also available under many brand names.  In fact, I used to administrate service contracts for a Volvo branded "extended warranty" product and even it called for the use of aftermarket parts when available.  Vehicle manufacturers are prohibited by federal law from voiding a warranty for the use of aftermarket parts unless they can show that the part is actually inferior and has caused further damage to the car.  
If you would like to give me some more info on the specific year/make of the car and the parts in question, I may be able to share more info.
Good luck and I'd appreciate your feedback.