Link Intime — Dividend not credited in my demat a/c

Address:

Kolkata, West Bengal, 700019

I have some share of mahanagar gas ltd which i receive by applying ipo. I have my demat a/c in hdfc bank through which i perform my trading. I raised my concern to the bank in which they replied
"corporate actions like splitting of shares /buy back offer/ disbursement of bonus / dividend etc. Are executed by the respective company / registrar & transfer agent in coordination with the depository (Nsdl / cdsl)."
In this case my registrar company is link intime pvt ltd.
I tried to contact this company several times through the no. Bank provided. But they didn't receive my call.
Could you please let me know how i could register my complain to get my dividend.