How do you Save and Retrieve Voicemail?

[DAEverett]

I subscribed to a plan to receive messages for my political campaign office.  When I test it by dialing the number to leave a message, the greeting message plays, followed by a system greeting message.  After I leave the message, I cannot retrieve it from the desktop or my cell phone. 

How can I fix it so that my custom greeting is the only one heard and I can playback messages?