Is cancelling a phone interview a common practice?

I was supposed to have a phone interview last week, and nobody called (allegedly the interviewer was in an important meeting). After 30 minutes of waiting I contacted the HR, they apologized and rescheduled for today. However this time they sent an e-mail 30 minutes before the interview was supposed to happen, cancelling the interview and saying they already found the applicant.

Is this kind of behavior common? Should I even reply to this kind of message?

No.

This is impolite and unprofessional.

You don't want to work for a company that treats job applicants in this manner. They probably treat their employees even worse.