Service has been bared

Location/place: Pune

Name of company/service: Airtel Mobile

I have airtel mobile number 9860249231 for which service has been bared by Airtel without any reason. And when trying to call customer care they are not responding. have lost much money to just call the customer care but they are not even attending the call and saying that customer care lines are busy. have tries aprox 20 time to connect to customer care but no use of the same.
Want to lodge leagal complaint against Airtel as they have given me a lot tension and due to them was not able to get any calls from anyone.