Hero Cycles — Hero D.T.B cycle complain

I have bought one week before on 01.06.2017 a hero d. T. B of 6 gears its fork nickel was been started removing i complaint to the dealer but he didn't listen me. The cycle cost was 7300 rupees. Please help me to do about this. My phone number is [protected]. The shop address is m. P. Devadi road, bhagalpur, bihar. The shop name is bhagalpur new cycle stores. The shop mobile number is [protected].
Your faithfully,
Ramji singh,
Janki prashad lane, mundichak, bhagalpur812001.
Mobile number - [protected].