AMC charges provided but services are not provided as per agreed contract

Rubicon services has entered an agreement with us in Oct 2013 for 3 years for providing AMC services for water purifier. The agency has provided service for 1 visit instead of 3 visit. We are facing some problems with acqua guard machine. We are calling them up daily since last 5 days but they are giving a false statement that somebody will come. Nobody bothers to call or visit to see the machine. We are fed up in follow up. Now they are not answering our calls.