Sony India — Faulty sony xperia c4

Address:

Mumbai City, Maharashtra, 400014

I bought a sony xperia c4 black 2hrs back frm CROMA store at lower parel phoenix mall..cant believe it when i call someone or recieve call the screen disappears
Cant dc the call as well..even if i press the lock button & try to unlock it..nothing happns..finally whn i plug it for charging the screen appears & when i unplug it the screen appears & phone is normal...need help in urgency