Welcome to the club. I bought my phone last October 12th and exactly after the warranty period + 10 days my phone failed the same way. No call is possible and I keep getting the same message always. I took it to ATT.
Though the plan contract is for 2 years, the phone warranty is for 1 year only. Apple store said the same and said I could buy a new phone for another $300 or so.. It is such a frustrating experience. The phone looks new. It is simply hardware failure. It seems like both Apple and ATT are telling me, I should have bought the insurance.
This Apple is lemon for me. I am so frustrated and want to throw the phone and say good bye to Apple.