Cognizant Technology Solutions — Offer letter not received till now

I am Simran. I have attended a round of technical interviews on 4th December 2021 and got confirmation mail saying that I got selected and to submit the CIS form to proceed further, then I have submitted the CIS form with required details and replied back.

Later on 7th December 2021, I got HR call and discussed about my package and designation, after that HR confirmed that they will release my offer letter in 15 business days, but it's been almost a month now and still I haven't got my offer letter and also no updates.

Please help me in getting the offer letter.

Thanks in advance.