Cognizant Technology Solutions — cis form submitted and got selected mail but offer letter not released

Address: Thoraipakkam Cognizant, Chennai, Tamil Nadu, 600119

On 12th may i have attended interview with cognizant for chennai location. And on 18th may i filled and submitted online cis form.

On 22nd may 2019 i received mail from cognizant that i have cleared interview process held on 12th may 2019 and after business unit approval they will send offer letter.

During the final round hr told within 10 working days i will get offer letter. But it has been already 2 months and not yet received offer. Even i had sent mails to hr but no response from them don't know what to do... Kindly help...