Got a call - no message

Got a call...they never leave a message.

Received a call from this number but they do not leave a message.

This troll called me in the middle of class and I didn't pick up, but they didn't leave a message. Then when I call him back to tell him off, he says that he is apart of the IRS and I'm going to be arrested in 45 mins.

Well this is the perfect example of why you should have your phone turned off and all your attention on the teacher.  That way you can learn something which will help you be intelligent enough to avoid these scams.