I worked with IMRB for around 2-3 moths and did door-to-door surveys for them in 1991 summer vacations. IMRB was handling a project of Indian Oil Corporation and we had to visit the homes of 30,000 of Indian Oil's kitchen Gas (LPG cylinder) customers about their experience with the service of gas agencies/distributors. At that time I was very poor, that is to say the least. Industries like IT or BPO didn't exist at that time so there were not many options for making money available. Most of Indian Oil's customers were highly dissatisfied with the gas agencies due to issues like late delivery of gas cylinders and we (IMRB's employees) were abused by many of those customers for no fault of ours.Now it appears that IMRB, which is a market research company, has been hired by Airtel to do customer feedback studies. If you don't like IMRB's phone call then just politely tell them at the start of call that you don't have time and hang up. Most likely IMRB's project will be over in 2-3 months when they would have surveyed the required number of customers and then they will be gone. No use yelling on them and such. Provided you can spare some time, another better option will be to give them grossly negative feedback about Airtel's services and may be that will help the company understand that they have issues.