Meru Cabs — Extra money charged with no intimation

I booked a cab from Indra Gandhi Airport terminal 2 to palam vihar Gurgaon as asked on the counter the fare was 580 but when the trip ended the bill amount by told by driver was 955 and when i called in the customer care there was no helpful response as the representative said your car had a long route which is why the price is higher the route was taken by the driver in which we had no say so why should we be charged the extra amount just because of the decision taken by the driver