I, as many of you it seems, was an early adopter of ios 7
Upgraded from ios 6 on T-Mobile without incident.
A short while later I began receiving this cryptic alert: Visual Voicemail currently unavailable.
Further inspection revealed the "Greeting" function was crippled" couldn't play it or access it
to change itthe page just locked up. Rest assured, however, all your voice mails are intact
just not visible.
My first impulse was to side with all the circulating ios 7 bug reports and find fault with Apple.
Half an hour on the phone with T-Mobile support (they were stumped) led nowhere.
Subsequently, independent action revealed (much to my chagrin) the fault was mine.
Mea maxima culpa.
I habitually turn offf Cellular Data in Settings, believing this to extend battery life.
Therein lies the crux of the problem. Cellular Data must be active for Visual Voicemail to
function. It took much digging to arrive at this simple truth, but there it is.
Interestingly, this was the only reference I could find that touched upon this aspect.
I am not offering this as a panacea to all your voicemail ills,
but I do hope some of you may find this, as I have, to be an idiot-simple solution.
You can find the nugget I uncovered here under Check Signal:
http://www.apple.com/support/iphone/...ail/#section_1