Disconnecting My Mobile Number

I am using Airtel postpaid and getting network issue i.e I am not getting network in my home and even I live in center place of Bangalore(BTM Layout). If I want to talk with somebody, I have to go out and talk with them by walking on street. So, I raised complaint 8-10 times, Nobody from Airtel contacted me. So, I didn’t payed monthly rental and It was pending from last 3 months. Now they are calling me to pay bill and giving warning about disconnection of the mobile number.