Puma — faulty puma backpack.

Address:

Pune, Maharashtra, 411046

Purchased a puma bagpack from flipkart on 26/10/2017. After using the bag for 2 3 days the stitches came out and i cant use it anymore as it may get damaged futher. By bagpack is under warranty. I need to claim the warranty. For warranty claim
I went to puma store but they did not entertain us. So what should i do now?
What is the process and where should i go.