Samsung - Samsung Ultra screen blackout

I have bought samsung S** ultra mobile phone * months ago, now phone screen blackout suddenly.
I have visited nearest authorized sansung service centre in sadar bazaar jhansi and deposited the phone. After lapsing of almost * days, no fruitful response received. I have already spent Rs. *.** lakh for this phone and within * months it stopped functioning. Such incident is unexpected from a brand like samsung. Expecting early response for my loss.