Accident Damages Compensation

Almost a month ago My car was hit from behind by a car drive by a lady with two kids. She was sorry about it and he and her husband agreed to pay for the Expenses after raising my insurance. So I did not go to police. Total expenses came to 25K and after insurance out of pocket expenses were 9k. I had shared all the details right from the beginning about car garage, garage estimates etc. Now the lady and her husband arguing the cost is too high and that I should have told how much it would cost after insurance in the beginning itself. They also enquired the garage and got all the clarification. After much discussion they started with Rs.1000 and willing to pay Max Rs.3000. It is absolutely not acceptable to me. I would like to go to police and if required drag them to the court. I know it is not worth In terms of time and money to go through all this but it has become very usual to hit and then not pay for the damages which has become driving unsafe and lose economically. This is the fourth time I am facing the issue without any fault of mine. Is it possible for me to raise 3rd party insurance to claim the remaining expenses not covered by my insurance? Please suggest the steps forward, rough timeline and the cost involved. Can the legal cost incurred be recovered from the opposite party? Why a person should suffer because of fault of someone else and go through the pain of time, money and inconvenience while the offender is roaming free? Appreciate quick response and honest guidance to a law abiding citizen.