Cognizant — offer letter not received for stibo position

Address: Thane, Maharashtra, 421306

On 4th jan 2019, i had my technical telephonic round. After 4 days hr had told me that i had cleared technical round and shared cis via email. I have filled all my details that cis and emailed her.
After that i have received a url from cognizant talent acquisition to upload my photo in there portal.
Yesterday (24th jan 2019) i received a call from chennai cognizant team that we have initiated offer letter already but when i had check my email i didn't found any mail from cognizant.

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