Airtel executives harassing customer

Location/place: Mumbai

Name of company/service: Bharti Airtel

I have been using airtel as my telephone operator for five years now. However, in the month of May 2012, I received a bill for the amount of Rs. 7,900/- The company charged this on account of data usage charges. I repeatedly tried calling up the customer care executives trying to tell them that this is an incorrect bill amount but they would not redress it. My services were cancelled by them. In return I have written emails to the Airtel nodal officer aswell from whom no reply was received. Hence, as a last resort I had to discontinue the number and switched my mobile operator. However, afetr a couple of days of discontinuation, The airtel executives started calling up my contacts asking them for the bill amount payment. These are my professional contacts and hence I was liable to a lot of explanation as to why these calls are being made to them. On contacting the airtel executives they said that there was a mistake in my bill amount and my actual bill was Rs. 2000/-. However, this harassment has caused me a lot of inconvenience and mental anguish. Please provide a solution for the above. They now say that if I do not pay the bill amount they shall continue calling up my contacts.