Cognizant — About date of joining

Hi,
My candidate Id is 14247332. Myself Sonali Balaso Desai. I got the offer letter after that I received the credentials to cognizant login but not able to login because of troubleshoot problem at cognizant 1c onboarding portal. For resolving this problem I mail to cognizant team as well but still it is not resolve.
Here I attaching offer letter for understanding as well.
Kindly feedback for date of joining will waiting it from long time.