I'll repeat what I posted earlier. Trust me, I see this stuff everyday in court. I had to do it as well years ago. Take the largest estimate (here in VA, you only need one estimate--the largest of course) and add a week's rental car (call Enterprise rental or some place like that to get a quote). If you lost any time off work, add that.
If you chose to consult an attorney- add that. Add all things things together and come up with a figure. Find out who the registered agent is for the insurance company--every company must have an RA registered with your state's corporation commission so that it can do business in your state. File a Warrant in Debt at your General District Court (or low court, or small claims, whatever your state calls it). The defendant will be the insurance company, it will be served at the Reg. Agent of the corporation. There will be a court date. Have pics of the truck before and after. Put that figure on the Warrant in Debt when you file for it at the court house. There will be filing fee--add that to the judgement request as well.
Once the insurance company see this Warrant in Debt came to their registered agent of their corporation, you will get a call and they will start to deal with you. That is the only time they will start to deal with you. Again, that is the only time they will start to deal with you. They know you mean business. They don't want to incur the expense of the corporation attorneys, rental costs, loss of work costs, etc...
Small print...this is in no way legal advise. I am not an attorney I just play one on a website.