USG Professionals Project Engineer interview questions

First a phone call interview to set the date for the interview with the HR. However, I was ditched on the said date, and I needed to give them a call to reschedule the interview because the interview organizer simply forgot about it, not professional. Then on the rescheduled interview, the process was fairly easy and transparent. The HR told me a follow-up email with more detailed information about the vacancy would be sent to me shortly on the same date. Of course, it has never arrived. Despite trying to reach out for response for multiple times, I received no feedback from them at all, didn't even get a single replied email. I would've been so much more OK with negative feedback than none at all. Extremely unprofessional.