Have you tried calling Verizon Customer service? That's what I'd do first.
If I tried that and got nowhere, I'd take it to my local Verizon corporate store and say something like: "This update that Verizon pushed to my phone has caused a problem. What is Verizon going to do about it?" The advantage of the in-person approach is that you're standing there in front of them with one of their phones that obviously has a critical problem...rather than someone who can't see you or your phone. It's probably important that it be a Verizon-owned store, not just a cell phone store that deals for Verizon.