Samsung Mobile Company - Mobile display not functioning within 9 months of purchase

Purchased Samsung mobile video invoice no CH*MP********** dated **..*..**** Suddenly the display has gone from **.*.** and hence contacted the service centres they said the motherboard has gone and refused to replace during warranty stating it's not manufacturing defect. I raised the issue vide ticket no. *********
No response till now , How this product has passed the quality test I do know. Need either replacement or my mobile should be rectified need immediate resolution as without my mobile I am losing lot of personal calls and stressed out .