NOV interview questions

HR dept was quick to set up interviews. First interview was via phone call with hiring manager, which she as very nice. Second interview was phone call with colleague. Third interview was in person and I had to prepare a scenario presentation. I got really good feedback and left the interview feeling great. However, the hiring manager was going overseas for an event. I did not hear back from them at all and felt that they wasted my time and effort. I sent 2 follow up emails to the hiring manager, but was ignored. I even emailed HR, but they did not have an answer for me. If it was the first interview then I would understand if the hiring manager ignored my follow up, but this was the final round of interview that I had put effort into. She could have the decency to let me know that they decided to go with another candidate.