Who called from 7813133465

called my cell, no message left

Called my cell phone - they left no message. Who are they?

Telemarketing call telling me I requested info on going back to school. I never requested any info and have no intention of going back to school.

Continually calls; annoyance call, no one's on the line when I pick up, no message when I don't.

They called my phone twice while I as in class. They don't leave messages and they don't have a dial tone when you try to call back. WEIRD!