I have been told by my travel agent that the visa section officials wanted to talk to me directly

over phone regarding my business visa. Hence I tried several times to contact them on the phone number ( 011-24675559 ) but I did not get through. I tried from morning 9am to 4 pm. Kindly advise how should I get in touch with them. I am in Chennai right now. I also tried another number ( 011-24674673 )