Gartner Recruiter interview questions

I was approached by recruiter on Linkedin. We had two (1 hour calls each) talking about the role and my experience. The third interview was with a Team Lead and it was competencies based interview. He was very rude and seems to be angry at me for no reason. After 3 stages of recruitment process and 4 weeks, they just despaired on me. No positive or negative email. I even followed up, but they ignored my email. I found this extremity unprofessional! Now I am thankful to them for not offering the job. Because I might have take it and I would make a big mistake. If they treat people like this at the interview stage, I cannot even imagine how would it be if I have joined the team.