5 rounds. Got to the 4th. Final round is in person interview in the office. Hiring - BDR manager - sales lead - vp of sales UK. Email rejection. No feedback given which was a shame

So, I recently gave my interview for the first round at Vertice and I had to speak about the unprofessionalism about the company or if I may say about the Interviewer. My interview was supposed to be on 4 days back in the morning but the interviewer emailed me asking me if we could postpone it for another day, understandable that he could be busy I said no problem then comes the day of the interview and I am waiting to join the meeting and he didn't come, I had to email him asking him to start the meeting. I already lost 5 minutes out of the 30-minute interview. The interviewer then came and by the face of it I could sense that either he is too busy to take an interview or they might have already found the candidate. The interviewer told me that the interview generally lasts for 20 minutes only so we still have 25 minutes. Then after around 16-17 minutes we told me if I ask any questions, I asked couple of questions and then the meeting got over. The rejection came with general feedback. I was fuming because firstly if they had already proceeded with other candidate then they shouldn't.t have conducted my interview and if they did they should be professional and punctual enough to be on time and try to actually listen what the candidate is saying. Horrible experience