ServiceNow Sr. QA Automation Engineer interview questions

This was four rounds, but I got rejected in the third (the technical managerial round). I couldn't understand why I got rejected, even though that was going well. But the interviewer wasn't mature enough to take the interview; she doesn't know how to take the interview (she was laughing with her colleagues and also busy with her work). She wasn't responding properly. Whatever she asked me, I gave her the perfect answer. But , simply, they are rejected. If the company goes through that interview session, they will get to know how the session was held. Why are these big companies doing this? Just playing with our brains and confidence levels. Please don't do this, please.and the recruiters are not responding when I am trying to get the detailed feedback(what's the reason)if I ll know the reason I ll change for the future.and I know noone will give response for it because they what they did with me.