Credit Card — credit card status:declined without any reason

Address:

Rangareddy, Andhra Pradesh, 500070

I got a call from hdfc bank for credit card, they asked about my details. After confirming my eligibility for credit card, representative visited my home filled all my details in a form and took all my required documents. Couple of days later i got sms with my reference number after that i got 2 verification calls.
Thereafter i did not receive any further update from bank.in credit card tracking website i checked the status it showing application status declined. I don't know the reason.
I'm very disappointed with the service