Third Bridge interview questions

Phone interview then an in person interview with four separate people (two interviews in the same day, each with two people). During the first interview I had to walk them through how I would solve a case study of theirs and my thought process. After not getting the job I reached out twice to obtain feedback and information on why I was not chosen but no one answered me. I felt this was a bit unprofessional especially because before the interview I was bombarded with emails and phone calls explaining the process, etc. but once they realized they did not want me, they did not bother to answer my inquiry. I understand I was not a good fit for the company but it would have been helpful to gain feedback from my mistakes.