Had 6 interviews they ghosted after telling me that feedback is positive and they'll be moving ahead with the offer. But from last 3 week they're not picking the call and no communication at all. I won't be joining even if i get the offer now

I did undergo 6-7 rounds with India as well as US team. The feedback was positive from the panel. The HR partner said he will come back to me with the offer letter, however in the end they were like we can't offer you this position but another lower position. But again that is not available so thank you for your time. This was pathetic experience as I felt I wasted around 10-12 days in the entire process. If they had courtesy to inform before, it would have saved time for their panel as well as candidate.