Have you noticed that you lack service when you're missing calls?
You could try to power down, remove your sim card and reinstall and see if that helps.
OK, I stopped by the Verizon store and asked about this. SO simple. On the little control panel that slides up from the bottom of the screen there is a moon icon. I had accidentally hit it and it's a do-not-disturb icon. Hence when I unelected it, it fixed my problem! SO SIMPLE!