The HR followed promptly and responded quickly.
There were multiple rounds of interviews, and the interviewers were different each time. Then, I realized that HR was to only arrange for the candidates and not was actively involved in decision-making or recommending.
There was a case study to solve. Irrespective of the background of the candidate, limitations due to lack of experience in specific fields, instead of review and feedback session, it was my way or highway attitude of the young guns who took the interviews.
Thankfully, I did not get selected, or else my life would have become a living hell under the high performing, one man army, the blazing cannon of the company.
By the way, I was rejected after 4 rounds of interviews, and no feedback for improvement or learning was shared. The news came from the HR that I was rejected in a simple one line statement over a phone call. There was no specific reason. That means for the first 3 rounds, they were just toying with the candidate.