If the code you showed is executing on a different machine than where the service is supposed to run (I’m not clear from your comments if that’s the case or not), you would need to provide the machine name in the ServiceController constructer.
Is it possible you are successfully starting the service, but not on the machine you think? That would fit the symptoms you describe.
ServiceController service = new ServiceController(serviceName, serverName);
Also see ServiceController constructor documentation.