Flipkart customer care service

I have purchased redme not 4 G, and its not working properly, like battery issue, camera, whats app notification, unknown ram issue etc.

I requested 4 time to flipkart, but its rejecting my refund request, finally i agree with replace but problem is same.

Now i am very irritated with this device.

new piece, still getting some issue, like camera and game lacking issue, etc.

friends please suggest me, what should i do for this problem !