Cognizant — cts - offer letter not released

I had attended interview on 13th july 2019, raheja mindspace, hyderabad.
I had cleared 3 rounds (Technical, manager, hr) of interview on the same day.
Even salary negotiation also done. Hr told that i will receive my offer within a week.
I have got auto status email says "cognizant interview status - select" on july 25th, 2019.
I received an email from cts talent acquisition to fill candidate information and upload photo
In one of their portal on july 26th 2019. It's more than 40 days since i attended the interview.
Still i haven't received the offer letter. Any one help on this?