ios 9.3.1 on iphone 4s update issues

Prior to updating my iphone 4s to ios 9.3.1, I began having issues with my messaging. I could send text messages (not iMessages) but could not receive messages (or would receive them sporadically). After updating my ios to 9.3.1, the messaging issue seems mostly resolved, but the phone app is messed up. When I try to call anyone, it goes into "calling iPhone..." or "calling home..." or whatever the designation is, then after a few seconds, the calls ends. It never dials. Anyone trying to call me, it sends it straight to voicemail. My TTY setting is set to off, so I know that's not the issue. Can't figure out how to fix it! Anyone have a solution for this issue?