Prism Software interview questions

Applied through agent. They called me for a brief 20-30 minutes phone screen, then gave me a coding problem. A week after I sent them the program, they emailed me to try to set up a phone interview. So I chose one time slot they provided, but later they said the time is not available, so I chose another one. Later they said it's not good again. So I chose another one, later they told me it's not available again. Very unprofessional and bad management. So I just told them forget about it.