Coolpad India — Coolpad note 3 lite software problem

Address: Dehradun, Uttarakhand, 248001

I am really very disappointed with coolpad note 3 lite. From the day one i bought this phone i am getting some problem every day with the device. I had visited service center 3 times they just do a software updateor something like that and after 2 or 3 weeks the problem again starts with the device.last Time when i visited service center they replaced motherboard of my device with a new motherboard but after 1 month i am again getting the same problem.
Problems:
1. Contact names in my phonebook changes automatically and i got call or text from somebody else and device shows some other name.
2.touch don't work after i restart my device for starting 20-30 sec.
3.battery backup is also very poor, my device lasts for almost 4hours if net is off, but if net is on then it hardly lasts for2hours.
My phone is in warranty, my warranty will expire on 29 march 2017.
I am just very disappointed and furstrated with this device i just want a replacement for my device or i will go for some legal procedures.