Cognizant Technology Solutions — Cognizant - Offer Letter not received

I am Aniket Kumar Gupta, I have attended of technical interview on 18th December 2021 .On 24th December 2021, i got HR call and discussed about Expirence, Package, current offer and Location after that HR told please share the current offer and confirmed me deviation offer will be recived in 10 -15 days. i received email regarding confirmation of offer and requet to share the current officer letter for approval of deviation offer letter.
On 27th December 2021, I received an email from HR, she informed me that the HR interview completed and offer letter will be issued in 10-15 days. She has also shared the details of recruiter email for further queries.

I have been following up with recruiter and HR since then but no response has been received till date and also have not got offer letter.