Schneider Electric Research and Development Engineer interview questions

I had attended the technical interview round, and it went pretty well for me, I answered all the questions posed by the interviewer and the feedback was very good too. I got shortlisted for the HR round, I had attended the HR round with full confidence and I did pretty well in that too. I didnt stammer while speaking nor did I say anything wrong in HR. But I still keep wondering why didnt I get selected for the role. Even after all these rounds of hardwork and excellence, I didnt get selected and to my best knowledge, I didnt mess anything up, I did my best and in the most perfect way. My question is that, if they didnt have enough vacancies for that role, why did they have to shortlist me till HR round and then reject me like that? The overall interview process was a total chaos. The technical interviews started around 9am for most people and were called slot wise, however for few, their panelist didn't turn up, therefore, they had interviews at around 6-7pm in the evening. While some people who had attended their technical round in the morning, got shortlisted for HR and finished HR by 6pm. It seemed like there's no point in attending the technical interview after that long wait as they seem to have "pre-decided" certain candidates and conducted the interview for the left out candidates just for name sake. Not just this, at many places, I personally felt they had favored a few people who actively participated in the Preplacement Talk. Very bad experience, no transparency at all.