People Group Node Js Developer interview questions

First Round is Simple Data Structure Question and then Second round was full of technical questions related to Javascript , databases , and the questions related to projects and technologies used and then the third round was a system design interview and my all rounds have went well even I received shortlisted status after the second round but after that I did not received any update I called Hr she told that Head of Engineering is busy whenever he will be available we will schedule your next round with him she kept on saying this for 2 weeks and then in 3rd week when I asked the status update she said you are rejected you were kept on hold . Very bad experience and unprofessional experience from team and they didn't gave any reason why I was rejected my rounds went well if they wanted to reject me they why to keep someone on hold for 2 weeks and that too without telling them.