[Resolved]  Bajaj Xcd 125 — vibrating sound

I Have got the bike from Rahul Bajaj(begumpet Hyderabad) on 14 october 2008 and its hardly 7 months over. Theres a sound i.e vibration coming while raising athe throttle...i have given my bike for servicing for more than 3 times but the issue was not resolved...infact they are blaming the company saying that its a feather weight bike...and it will vibrate but it wasn't from beginning...

so plz take care of the issue...dont put down the company's reputation...
I will be obliged to you...