Beginning five days ago, I started having issues with being unable to send text or call out. I have checked that iMessage is on, I have reset the phone several times, reset the network settings, turned cellular service off and back on, airplane mode on and off, bluetooth is off, wifi is off and do not disturb is off. I have roughly three bars for service. The phone periodically snaps out of it and allows texts to come through, allowing me to text and make calls, and suddenly it will not allow again. Is this a SIM card issue? Software/Firmware issue? I currently updated to 6.1 (10B142), but this issue was taking place two days before that and upgrading didn't solve the issue. How do I fix this issue? Is it a problem with the iPhone or a problem that Verizon can fix? Help!!