Hero Motocorp — poor service of vehicle

Address:

208014

I own a scooty duet that i purchased 2 yrs back.. I have submitted my vehicle multiple times in the service centre. But my problems always remain unsolved or they again arise after a week. Really fed up with the response i have got from my purchase. Its really inconvinient and sometimes it becomes really troublesome to carry the vehicle in every ten days for one or other problem.
Sometimes there is a mileage issue or sometimes it has a backfire issue.
Recently it has given the mileage 25kmpl.
I have paid thrice for change in parts but the problems are the same.
Feeling like selling off my scooty as if it was a big mistake.