Sunoco LP Manager interview questions

Had phone interview with hiring manager & was very impressed. Was asked to come into office to meet the team & work a case study to see if I was a good fit. I get there & spent 4-1/2 hours having 30-45 minute interviews with 7 people only to be told I’d be emailed the case study & I have a week to complete it and come back to conduct a formal presentation. I read the instructions several times- it’s basically solving the main concern I was told if I was hired I was expected to work. Who asks an interviewee to work/solve a real problem as a test to see if you’re going to get hired! So I ask am I really supposed to put in the work to solve this plus drive in & present my solution to stakeholders. Answer was yes plus explain why I took the steps I took plus please call as many existing staff as possible to ask as many questions as possible. No! I don’t work for free & especially not working a real current issue before I’m even hired.