Amazon Sr. Product Manager interview questions

I was referred by an employee for a couple of positions at Amazon. I had a telephonic interview within a week. It last for an hour ( a few minutes longer). It was a combination of experience and small case/scenario type questions. It was a fairly challenging interview. The interview was professional and to the point. However, I was disappointed by the fact that neither the HR nor the hiring manager followed up with me after the interview updating me of the status. After following up from my side, I was asked for another telephonic round interview. It was basically similar in nature. However, no follow-up afterward. I was disappointed by the unprofessional behavior Amazon showcase by not contacting me or replying to my email/call to HR. I was never told the status of my second round interview. And I had to assume they selected someone else.