Wireless radio won't turn on - phone no longer works

The phone function in my Audiovox SmartPhone 6600 suddenly stopped working after 13 months of use - everything else works fine, but it says "No service" or "phone off" when I try to dial a number. VerizonWireless says there is no trouble with my account. It also freezes up and requires a restart when I try to access the phone settings. When I dial ##778 it says "The wireless radio is currently off. Please turn it on!", but I can't find anything in the manual or anyone at tech support that can tell me how to do that! Any ideas would be appreciated. Thanks!
audiovox 6700 phone off. when i dial its says wireless radio not attached. what do i do