Student journalists are not students for very long.  By this, I mean it only takes two or three years from the time you brush off a student journalist until the time that same journalist is working as the new marquee columnist at the national newspaper.  People hold grudges.  Two or three years from now, would you remember someone who was rude to you or refused to respond to a request?  I know I would.  So when a student journalist calls tomorrow, answer the phone.