phone not receiving calls!!! please help!

[s1l3ntm0use]

So it started on Thanksgiving day, but it's happening pretty much all the time now. Someone calls my phone but I don't get a call, at most, the music that I'm playing stutters a little bit or the phone lights up when it's asleep but I get no ring or notification. All I get is the voicemail alert if someone leaves a message. WTF is going on?!?!?!??! My friend had to take a cab home from the airport cause he couldn't get a hold of me