Hero Motocorp — completely dissatisfied with hero service centre

Address:

Bhumi automobiles patratu

I have purchased a glamour bike. My bike registration number is jh24d5101. When i had purchase bike, my bike give milage of 54 kmpl. But during the 2nd service in hero service center the mechanic disturbs bikes milage. Now my bikes milage is 34 km per liter. I am facing this milage issue from 2nd service time and i am also complaining for the above problem on each and every service time of my bike but my problem not resolved yet. Everytime service center cheated me with fake sympathy. Due this i am facing revenue issues expending lots of money on petrol. So please kindly help me...