Cognizant — My Date of Joining is not updated.

Address: Chenni

I got selected for IT SD role at cognizant. I completed all my pre-joining formalities and my DOJ is on Aug 17, 2021.
I had meeting on joining date of document verification. I couldn't join the meeting exactly at given time due to technical issues. I joined late by 20 min. The HR has left the meeting without verifying my documents.

Now I didn't get the Cognizant employee ID and I'm not able to join into the SD Internship.
I sent no. of mails to the concerned team. But, Nobody is responding.
Please help me out with this.