Cognizant Technology Solutions — release of offer letter

Address: Hsr layout, 560102

I was interviewed on 11th may 2018 at baghmane tech park (Bangalore) for informatica developer role in cognizant.
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 can expect the offer letter. It has been 4 weeks now and i have not received any reply from them.

Kindly let me know the status of my offer letter.