Visual Voicemail on Galaxy S3

I have an issue with my Galaxy S3 that perhaps can be resolved here.  I already tried calling support, but they were next to useless as their information was apparently outdated.

Backstory:

I purchased a Galaxy S2 Skyrocket back in November 2011.  This to my knowledge was the first Android phone I have had on at&t (previous phone was a Captivate) that included the Visual Voicemail app.  I was happy for this as I previously had an iPhone and missed the feature (ended up using Google Voice and later YouMail to restore this functionality).  Anyway, used this up until this month when I acquired a Galaxy S3.  Again, it had the Visual Voicemail app on it.  Set it up, worked great.  Only problem was they only had the blue phone and I really wanted the white phone.  So my wife was eligible for an upgrade and she prefers blue anyway so we went down and picked up a white phone, did some swapping and voila, got the phone I wanted, no big deal.  It's also a Galaxy S3.  While we were in the store I mentioned to them that my wife's voicemail never worked.  They checked on it and fixed her access whlie we were there.  i went ahead and setup the Visual Voicemail app on her phone and things were good.  Went to set it up on mine and it never work.  It goes through the process of setting it up and then fails to verify me.  One curious thing to note was that while the first S3 included the app, the second one did not.  It is available on the Play Store for download since it's apparently an eligible device.  Both phones included the at&t Messages app.  When I called support they said that the Messages app is what I am supposed to be using.  Messages works, but I hate it because it hijacks the SMS system.  It basically prevents the default SMS program from receiving text notifications.  I just want plain simple visual voicemail.  Is there any way to fix this problem without resorting back to Google Voice or YouMail again?  I don't understand why at&t has to make something so complicated.