I'm sorry to hear that you aren't getting any service on your device. May I ask where are you located when you get the msg, City & State. When did it start? If I can have you elaborate on the issue it would be greatly appreciated.
Make sure you're within Verizon's network and/or roaming area.
Also, if you're in a large concrete building or other type of structure that limits network reception you may also recieve this message. My droid 3 almost always displays a notification about not finding any CDMA network at all and if I want to scan for GSM networks (it's a global phone) when I'm in the parking garage at work.