Majority of my calls going straight to voice mail instead of ringing

[AC Question]

Majority of my phone calls are going to voice mail instead of ringing. I don't know that I have received a phone call until I see the voice mail icon. I have checked the sim card to see if it was loose it isn't. I have switched off the LTE version still doesn't work. Any suggestions. This is a Straight Talk Samsung Prime Core phone.

 

[NexusIsMasterRace]

Make sure you are not in airplane mode and that you're sound isn't turned all the way down to DND (do not disturb) mode.