Who I have the same questioned this topic

So I got an iphone 5 (upgraded from HTC incredible) in Dec and just found out today that my voicemail dose not seem to be working.  When I dial *86 I keep getting the automated message "Sorry your account has no access to the system.  Please consult your system administrator."  What dose this mean and how do I go about fixing it?  I didnt have a problem on my Droid but now on my iphone I cant seem to get it to work.  I even tried to dial my own phone number but got the same error message.

Who would my system administrator be?  Is that located in my account somewhere?

Thanks for any help

-Anthony