Cognizant — got selected but didn't receive the offer letter or welcome mail

Address: 560027

I had got selected for asp.net developer with azure on 23rd see 2018 (Sunday) at manyata tech park bangalore. Salary was discussed, i had settled for the salary they offered me. Everything went really well but i have not got the offer letter or welcome mail till now. I see that few people have already got the welcome mail and offer letter as well. I tried calling the on boarding team they just ask me to send an email. I did send the email but no response till now. I also tried contacting the hr but no response. Just want to know the status of my application.