Writing dilemma

This is the first time I am facing this dilemma and really am not sure what to do with it. I have been assigned my first article with a magazine and need to interview somebody for their inputs but it looks like the person I am supposed to interview is not much of a professional. They keep confirming times for an interview but when I call, I am asked to reschedule. Emails are of no use as they wont respond to that. Typically when someone is being featured in media they are very professional about it but this person clearly does not care one bit. On one hand, I want to stick to this no matter what as it is my first experience writing for this new magazine and I'd like to have a long-term association with them. On the other hand, I feel like a professional who is this unprofessional is really not worthy of a magazine article. What to do? My deadline is tonight!