I recently acquired a Nokia Lumia 520 from Koodo. When I try to recover my voice mail messages, I am able to go to the voice mail screen, but the display screen goes blank, but the audio continues. How do I keep the display screen on?
I had a similar issue with my Nokia Lumia 800 and was able to see the screen again by pressing the back button at the bottom and click on the call to see the call screen. After I updated to the latest firmware, I no longer had that issue, you might want to try that.