Cognizant — application status under review

Address: Pune, Maharashtra, 411057

I gave interview on 18th nov 2018 in s. B road office, 2 technical round followed by hr round. All went well. Hr said as i am ex-employee, it may take 1 week to process for approvals. But do not hear anything till date except auto generated email that application is on hold. What is the reason for "on hold". At least hr could update during interview itself. I did not ask much hike. Guys why do you just take the interview if simply you put the application on hold without any reason. I am ex-employee of cts and had good impression, but now this is very much disappointing.