Supporting Strategies Financial Operations Manager interview questions

It was a series of 3 interviews: one over the phone and two through Zoom. Initially I had to complete an accounting skills test and a personality test. Then the first phone interview went very well. I was instructed I needed to become Quickbooks Online certified. I spent an entire weekend studying and then became certified. I notified the contact person that I am now certified. I didn't hear back for a week then they scheduled a Zoom interview. The Zoom interview went very well. Then I was told that I needed to provide 3 references which I did. After that another week went by as I had to wait for an associate to schedule a third interview with me. The third interviewer finally scheduled with me for the next day. About 30 minutes later, I received an email stating they had chosen another candidate. Flabbergasted, I asked the original point of contact and the third interviewer why that was the case when I just scheduled a third interview minutes ago. No one responded all day. Then about 30 minutes before my scheduled / then canceled interview, I was told that was an error and I still had an interview. The third interviewer seemed unpleasant and not very personable or professional. She was wearing a t-shirt for the interview. Most questions in the third interview dealt with disciplining employees and firing people and very few dealt with my skills or abilities. Another week went by and they emailed me saying they once again chose another candidate. Seems like a waste of time to require someone to get a certification and provide references that early in the interview process to ultimately tell them you aren't interested in them. It was also unprofessional at times to tell me they chose another candidate to then say it was a mistake to then say they did in fact choose another candidate.