Hilti North America interview questions

I had two phone interview and two face to face. Interview questions and people were pro and responsive. Questions are mostly common and you can find it every where, like tell us about the time you made a mistake, the time you had difficulty with your co-worker, your achievements and ... At last interview, the Technical manager who interviewed me at the end of session told me I am pretty confident that we will hire you and you can go out and talk to our people and discussed about the job and.. but when I email for thanks and follow-up without any clear reason she emailed me back that we can not offer this position to you. It was kind of unprofessional to me, I never had an interview without feedback, it is very polite and ethical to tell the people why, Again I sent another email and thanks for the time and interview and politely asked for reason to improve myself and there was no response. Then I felt like humiliated. It is not professional to give someone hope and then simply say no. Before this interview I never believe people`s word about Hilti but know I can understand why they negatively talk about hilti.