Cognizant — no offer letter received after selection

Address: Bangalore, 560098

I have attended cognizant off campus drive on 29th march in cambridge institute of technology bangalore. After clearing all the rounds i was selected and told that i ll get offer letter in a week but i haven't received it yet. My name is ankur singh from jssateb. I m waiting for the offer from along time kindly help me. I m studying jss college bangalore.