Updated iphone 4 to iOS7 ending phone calls?

I can do everything on my phone from receiving messages and sending, but i can't make phone calls. It does not ring it only says "call ended". I can't receive calls either it sends the other person straight to my voicemail. What is going on? Any suggestions?

Call your wireless carrier…

did you do an itunes factory restoral before or after the ios7 update like a good little iphone techie? If not, do this first before calling your wireless carrier. 999999999.999999999999999% of the time, major updates require a reset. I don't care if its an iphone, android, windows, BB, or a $20 walmart flip phone! Major updates require a reset… And I challenge anyone to prove me wrong

major updates require a reset

Turn off the fone. And when you turn the phone press home button and on button at the same time. When it starts turn Wi-Fi on and make a call… This worked for me… Hope i helped.let me know what happened to you.