Honda 2 Wheelers India — acceleration problem to my x blade in 4th or 5th gear starting from 40 km/hour and up to, 55 km/hour speed

Address:

Pune, Maharashtra, 411014

Acceleration and speed when riding
I took a new HONDA X BLADE (Black Colour) Engine no ********,
Chassis no ********* from Gagan Wings HONDA, Wagoli Pune on 2nd of july, 2018.
I have been experiencing some irritating problem when riding my new X BLADE.
When I am accelerating my X BLADE in 4th or 5th gear starting from 40 km/hour and upto 55 km/hour speed,
my bike is not taking acceleration smoothly and the speed is fluctuating to a remarkable extent.
And when I drive my X BLADE above 55km/hour (for example like 60 or 65 km/hour speed) steadily then also the speed is fluctuating.
I am very much worried about this problem after buying a new X BLADE and feeling irritated.
I like to draw kind attention of the relevant authority in this regard. I also given my bike two times to the service center but they failed to solve the problem.
Its my humble request to the relevant authority to take necessary action regarding my problem.