Cognizant — no communication from hr for long time

Address: Chennai, Tamil Nadu, 600062

Website: Www.cognizant.com

Hi, i am sudharshan, i got selected on a direct walk in held at kandanchavadi chennai on october 13th, then received a confirmation mail that i was selected on 15th october. After this i received a mail invitation for live interview with cognizant" date :nov 8, 2018
I was informed that the hr would be reaching out regarding my status

I received a call from cts hr through phone :[protected] on 13th november.

I confirmed that i could join within 15 days.

I was informed that they would send the offer letter after getting approval from hr poc.

They didn't mention who is my hr poc
After all of this i received a mail to upload my photo on 23rd november

After all this i didnt receive my offer letter yet

My contact details
[protected]
Mail
B. [protected]@gmail.com