Xiaomi India — phone not working in 6 months

Address:	Mumbai City, Maharashtra, 400071
Website:	Xiomi

I bought xiamo note 3, in december and now within less than an year the phone's motherboard is not working.
1. Cannot hear the noise when speaking on phone.
2. Not able to connect to wifi.
3. Display isn't proper.

The phone is still under warranty and still mi is not willing to fix the issue.

I am from it background so i could figure out the reason for failure.
Is there any solution to this? It is still under warranty fyi.