Consumer Redressal

I have purchased a new car NISSAN SUNNY Diesel in JAN 2012 from ASTER NISSAN , BARODA.Registration number is GJ23 M3551. At the time of purchase,I have taken full insurance (NIL DEPRECIATION it means- if an accident happens all the expenses will given by insurance company and not the owner of the car) My car has met with an accident and I have given it for repairing at ASTER NISSAN, VADODARA a month ago. Now they are asking for repairing money from me. Now what to do in this case please help me. I will thankful to you.