Voice mail can be like that. There is no rule or standard that enforces a return phone number to be on screen. If they can't bother to leave a number, well, they'll call again if it's important.
I have a free safelink "Obamphone" and I can never find a caller's phone number displayed anywhere when I access a voicemail. This is particularly maddening when they say "call me back." Now of course I know that there are ways to block a number from showing, but if that isn't what the caller did, isn't it standard for his/her number to show up somewhere on the little screen thingie? Or is that just peculiar to safelink phoes? I feel so stupid even asking. I am an old person.

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