How can I get some value for my used smartphone in India, Delhi?

[AC Question]

Hi, I live in New Delhi (India).

I am looking to sell my OnePlus One 64 GB.
I have tried selling on OLX & Quikr and its been 5 days, but getting calls & notifications from dealers only.

I am not comfortable selling my phone to such people.
Can any one suggest me a better and alternate option?