JetBrains Senior Software Developer interview questions

Applied via some job search site in Russia, got an invitation from HR to book a call, booked call, got email from HR with confirmation of the interview. On the planned date and time HR did not call me. I dropped her an email with a question, if we going to have an interview, and got nothing back. Very unprofessional behavior, never seen it before. No apologies, no email, just wasted 15min, while was waiting for her call :)