Bajaj Auto — discover 150 f, low mileage issue

Address:

Pune, Maharashtra, 411014

Its been 2.5 yrs i am using this bike and the max average i get is 40-42 km/pl. Can i know what mileage i should expect from this bike?
I have serviced this bike regularly at mittal auto, chandan nagar and then at gems bajaj, hadapsar. Both these places i have complained about the mileage problem, but none of the above service stations could resolve the problem.

Please look into this and let me know if this can be fixed and brought somewhat near to what company claims an arai fuel efficiency of 72kmpl.