Volkswagen India — Fuel delivery system

We have Vento Diesel Highline Regn No - DL 10CC 0890, one day some caution lights started glowing and the car was brought to the workshop, we were told that due to adulterated fuel, the tank has oxidized and metal pieces are found in fuel delivery system of your car, later we asked for samples of fuel for testing, the dealership refused and gave us a budget of 3 lacs to get the car repaired, after a lot of hassles the proposal was given that vw will bear the parts and you have to bear the labour charges which was around 40-45 k, no explanation was given afterwards, it was just a offer made to us and we had to get the car repaired as we are dependent on it, but we feel cheated by VW as no explanation were given by their end and they refused to give us the samples, either its a negligence at VW ends, their parts are not superior or its a fault at workshop end, and after 2000 km the light has started glowing again.