Cognizant Technology Solutions — offer letter not received from cts

Address: Hyderabad, Telangana, 500089

Was interviewed in cognizant hyderabad campus for big data developer role and
I cleared all the rounds and including hr round. They made me fill a form with all my details on the same day.
Hr told me that with in 1 week i will get offer letter. After some days i got mail from nihar shah (Hr) to upload my photo and details in their website and uploaded required. I got acknowledgement email regarding my selection. But i haven't received the offer letter yet. Its been 1 month now and i have not received any reply from them.

Kindly let me know what is the status of my offer letter.

My email: sathya[protected]@gmail.com
Phone:[protected]/[protected]