The message could not be processed. This is most likely because the action 'http://tempuri.org/ISas9Users/GetSasUsers' is incorrect or because the message contains an invalid or expired security context token or because there is a mismatch between bindings. The security context token would be invalid if the service aborted the channel due to inactivity. To prevent the service from aborting idle sessions prematurely increase the Receive timeout on the service endpoint's binding.
WCF Error: The caller was not authenticated by the service.
Make sure you use basicHttpBinding vs wsHttpBinding in your web.config if using WCF (which I am).
Also, you may need to check your XML and make sure you have the encoding defined in the XML header: