OnePlus India — Having problems since i have purchased the handset.

Address: Bangalore, Karnataka

I have been complaining that my fone is not woking fine from the day i have bought the fone. service center and oneplus is been telling me that the motherboard will be arriving their service center for more then 20days now. the have yet not given me any conformation about it. i called them more then 5 times but have got no call back. in oneplus india there a person named Mr.Shabbaz khan who kept telling me ill surely solve the issue, but i see nothing like that happening. they are not replying to the mails nor calling back nor they are providing me the contact number of the all India service manager. what can i do now? how do i fight for my rights? my contact details are mentioned below: E-mail:[protected]@gmail.com Ph no:+91 [protected]