Octus Client Relations Manager interview questions

A phone screen from HR. Then a 30 minute phone interview. Then coming in for a 90+ minute interview session with 3 different people in person. Then I was assigned a written case study that took 3 hours to complete on my own time. It was about 10 pages long when it was finished. Then I had to take this case study, convert it to a powerpoint presentation, and then come back to the office and present it to the entire group. Some of the feedback I received on this presentation: "Your case study was flawless." "Absolutely perfect." "You should see some of the case studies we get at this place! Wow! Talk about nailed it!" After that was 3 more in person interviews. About 3 hours of my time. Every interviewer was very positive to me. They all seemed like great people. And I did not get offered the job. They actually called me personally to tell me I didn't get it, which I suppose the HR woman deserves credit for just to have the nerve to do it, but all it did was get my hopes up that I was definitely getting an offer. What job asks to set up an appointment to call you to reject you? I actually said "Really? Why?" I was told there was no negative feedback, I'm just not hired. Which is odd. I honestly have no idea what their deal is and I feel like I've wasted a ton of my time, resources and PTO time from my current job to go through this. Every single person I dealt with gave me excellent feedback the entire week. Yet I didn't get hired. What a bizarre process.