Had you done, the calibration check, you sure would have been in for a surprise! I was exactly in your same situation, just a week back, when I got delivery of a new Swift(P), which has a capacity of 42litres, as per the specification. On filling up the tank, got the bill for 44.85litres. The difference could be in filling up the tank way above the maximum indicated limit, say as in, when the auto fuel cutter cuts off, & you still allow the pump guy to fill it upto the maximum visible level, you sure are to exceed the specified fuel capacity of your tank. This happens with most of the newly delivered cars, as they have hardly 3-4 liters of fuel in them. So it's not that the Fuel Station guys have deceived you. And please don't demand an explanation, as they might not be expert engineers to do calibration check. Go easy on them. Trust me, these days, it's hard to get fuel of good quality. Mostly, it's adulterated. So, if that particular Fuel station is reputed to have better quality of fuel, without any adulteration, do fill it up there again!