Pets Global interview questions

I applied for the position and within the same day, contacted by HR. I had a preview call and then another call with the HR manager and we set up a zoom interview. The call was with 4 company employees and myself. I thought the interview went ok. I must admit, it was not best. They took turns asking me questions, but there just didn't seem to be enough time to answer them fully. I sent a follow up letter the same day. Two weeks rolled by and I sent another letter, that was never responded to. That's fine, if you didn't think I was a match for the company and the position, just say so. I'm an adult and in sales, I can take rejection. But not to respond at all? I find that very unprofessional.