S4 can't place calls (still dials), often hangs, touchwiz stops working, etc

[Morario84]

So recently (this week) I have been unable to place or received calls. I can still dial and answer, but when I go to place a call I don't hear the ring and can't hear anyone on the other end when they pick up. When I go to answer, there's no communication and the call ends on its own.

Also, the phone freezes alot. Sometimes I get the message touchwiz (or another app) has stopped working. If I try to adjust the volume it hangs up for a good 1 minute or so like, its lagging, then comes out of it. I've tried a factory reset and clear the partition cache - these seem to have helped temporarily, i was able to make and received calls and the phone was working smoothly, but that last for a night. Reset and cleared the cache last night, it worked for the night, and today it's back to no calls and hanging. I ve tried turning on/off airplane mode, screwing around with network settings, nothing seemed to work. Turned off all motion gestures and stuff like that, still nothing.
Have android version 5.0.1, software version I545VRUGOF1 and config version J12.SAM.SCHI545.0 ... system updates says it's up to date.

I've done a fair bit of googling and tried everything I've seen out there.. Does it sound like a firmware issue? Something I can go to verizoin/bestbuy about?

 

[Morario84]

I should now add that the sounds randomly cuts out.. espcially annoying because i use it as my alarm. I just tested it - the alarm and sound goes off for like 5 seconds then stops.. needless to say I slept thru it..