My phone has said "No service" for the past 48 hours

I also am having this trouble. My phone has said "No service" for the past 48 hours. It says I must update my phone in order to get service. When I try to update, it gets stuck on "Verifying Update". It was stuck on Verifying update for 10 hours yesterday before I reset it. Now when I try to update it, it says "Unable to verify update" and that it failed verification because I am no longer connected to the internet. I have been on my wifi and my wifi always works great. My phone is still connected to the wifi and yet it still is unable to verify due to no internet? Something is wrong. I have already gone to General>storage>and deleted the update to try again. I have done that about 3 times already.