Who I have the same questioned this topic

I have the iPhone 6.  My incoming calls are going straight to voicemail instead of ringing through.  I need my children to be able to reach me quickly if need be.  I tried a reboot (holding the circle and power button down) until the apple appears, but the issue still continues.  I'm worried I shouldn't have upgraded.   Anyone else having this issue?  If so, how did you solve the problem?