Cognizant — cognizant regarding offer letter

Address: Chennai, Tamil Nadu

Hi,
This is selvarani.in january 20 2018, i had an interview in cognizant, varalakshmi techpark, kandanjavadi. I have cleared all the rounds and told that i'm selected. Then hr gave me a form to fill up about my qualification and contact details and told that i'll get the offer letter by email. I have tried to contact hr via phone call and emails but they didn't responded. I haven't received my offer letter yet. So, will you please help me out in solving this problem?
Email id:[protected]@gmail.com