Read my previous post.
You can argue with the insurance company all you want. They have all the time in the world, and pretty soon you get tired of arguing with them and you get frustrated and you wind up taking what they offer you. I know... I was in the same situation.
I tried telling them that the amount they were offering me wasn't fair. And I said besides, I don't want the money... I want my car back. Or one just like it. So they offered to find one for me, but all they came up with was "close but no cigar"... not the same color, not equipped the way mine was, etc. So after going around and around with them for weeks, I finally caved and said ok, give me the money.
Their line is this: we will pay you what we think your car was worth. What we (the insurance company) think it was worth.
Good luck trying to outmaneuver an insurance company.