How long does the driver legally have to provide a statement once an auto accident claim is open?

While driving in the fast lane (lane 1), a gentleman in the lane to my right (lane2) attempted to change into my lane and clipped the front end of my car with the rear of his car. His car stuck to mine for a few seconds as we slid into the median of the freeway. From a third person point of view, it would have looked very similar to a pit maneuver that the police use. But instead of my car applying the misdirectional force and bumping into him, he applied the force and spun himself out in front of my car. Half way through his spin, he was stuck to the front of my car until I was slowed down and eventually stopped by the sand of the median. His car went a few more hundred feet until also getting stick in the sand. Witnesses have the same story as I do. He said at that time that I slammed into him. Skid marks on the road prove otherwise as well. I'm assuming I was in his blind spot as he attempted to change lanes into mine. An issue has arisen with the claim process. Both companies have recorded statements from me, Both have sent out an agents to take pictures, and both have estimates to repair damage to my car. I have completed everything needed to be done from the driver’s part of it. It's been a little over 6 weeks now and the other insurance company says they have had no contact with the driver since the accident. They claim he has a lawyer but when talking to his claim representative, she said she has no info from him or any contact. How is this possible? How long can he legally be in hiding? A few days after the accident, he called my cell number (obtained I'm assuming from the chp's collision report reference card) asking for my insurance companies phone number. Since then, there was no contact. All I have is a liability insurance. My company has denied liability for the incident and says their job is done. My car is unusable as it sits as I'm missing work by the day due to lack of transportation. What do I do?