POET Systems Engineer interview questions

I was given a 30min phone interview with the head process engineer of POET. He asked me questions on mostly my graduate school research and my ~2 years of work experience in a similar company like POET. He also asked my if I knew about POET and what kind of research was going on. The interview went really well according to me and he even told me he would like to schedule an on site interview and will get back to me within a week. So I sent a thank you email to him and inquired after a week and a half after I did not hear from him after a week as he had told me. But sadly he did not even reply to my email. I was really looking forward to working in POET and was looking forward to the onsite interview but nothing came even after 3 weeks. So I emailed him again asking about the interview. Its been 4 months now and I still haven't got a reply. How much ever busy a person may be, or if he wasn't interested to interview me further, he should have atleast have the courtesy to reply back. I am highly disappointed.