Tvs Motor Company — servicing of scooter and mileage

My scooter mileage is 39/40. Company claims 62 but i never got more than 42 km. Every servicing time i complained about it, but service centre people are not serious. They requires only good ratings. I did servicing at koperkhairne services centre.. Last time when the servicing did even oiling was also done.
If company claims average of 62/km, i should get at least not less than 50/km. So kindly do the needful...