Airtel — Unsolicited calls in the name of property dealer

Some one with phone number[protected] is making calls in the name of property dealer and he keeps arguing for no reason.
My phone is on DND and out of that he called. When i told him i have not registered with any of the property dealer he said he have the number based on browsing details. I can definitely say that i have not looked for any property and have not browsed any of the website. Some times he tells he is from 360 and today he is telling that he is from 'pink *' some thing which i did not understand . when i have not registered anywhere why he has to keep calling and more over he is threatening. The way he says is as if i have to bear the call .this is 100th time in this 3 months he is calling. While my number is karnataka registered, he speaks in telugu also.