After upgrading my Lumia 620 with the Amber update the Visual Voicemail function went missing. (The cassette symbol appeared again, and there is no on/off VVM setting) I've been in contact with both Nokia and my phone operator (Netcom Norway) and they just point at each other. Anyone else experiencing this? Can I expect this to be fixed in future winphone updates, or is this purely an operator problem?
I use Verizon, which I'm guessing you do too, as I'm pretty sure it's a Verizon specific feature. Search the app store - there's a Verizon "Voicemail" app. If it's not installed, install it. If it is installed, then problem solved.