iPhone 6s camera freeze to blur

I had bought the iPhone 6s space grey 64 GB on the launch day here in India.

The reason I bought the 6s was for its camera as I was using 5s before it. Which had superb camera for an 8 megapixel shooter

But there is a weird issue with it. Sometimes when I launch the camera app (it's irrelevant whether I launch it from the lock screen or the home screen/springboard) it will stay freezes on a blurry screen, even when I change the shooting modes. Sometimes the issue is resolved when I kill the app from task switcher and start it again, but mostly I have to force reset the phone by holding the power and one button simultaneously.

I have tried restoring the iPhone as a new phone when iOS 9.1 was launched. But the issue persists.

I tried restoring the backup from iTunes. Again, the problem remains.

This is very frustrating because I really like to take pictures from the 6s camera and this issue just spoiled it for me. 6s costs a lot, for the people from US; it's sold here at $1,089, which makes me even more worried.

Kindly revert me with a solution or at least give some directive about how to approach Apple about the issue.