Cognizant — Offer letter not released after HR discussion

Iam Pavani Chemala
I completed interview from cognizant company for CIS Cognizant infra off campus- Graduate trainee/Engineer trainee the context of the TR and HR interviews that took place on 28/03/2022 and 29/03/2022 on superset platform.In HR had a good positive discussion with her regarding Package, joining date and Location.
It's almost been 3 months I didn't hear anything from cognizant I have raised query several times but of no use.
Therefore, I am writing this to request you to please send me a offer letter so that I can move ahead with other formalities. Or atleast tell me what's the reason for delaying