Airtel — Harassments from Airtel broadband

I dropped mail to CUSTOMER care and called CUSTOMER care multiple times to close my connection. Almost 10 12 hours it took for me to get hold of there executive to raise a cancellation request. Now they are asking me to pay the outstanding amount from current date. I raised a request week back and these ### played there dirty games to make sure i give the extra money and forced me to keep connection. Why there is no smooth way of closing any service. more than 50 CUSTOMERs in my apartment moved away from Airtel for these cheep tricks . The service is also horrible. it goes down once in every week and they dont refund the money also. what action we can take with these fraudsters?