Partners Real Estate interview questions

The job description requested applications be sent to an email along with a cover letter which I did and got a direct response back despite being one of thousands of applicants. They stated their excitement with my resume and writing skills and offered the next step in the application process, a skills assessment. To note, this is before any type of phone or video interview and should have been a red flag. Second red flag was the pretty in depth and time exhaustive assessments; 4 assignments including a motion graphic advertisement in multiple layouts and dimensions. Being that I got such a warm and appreciative email and the salary was above standard, I moved forward with it. Once I reviewed the instructions, I had a few questions, but after a week I still hadn't heard back (third red flag). I understand that people sometimes get busy, so I pressed forward and made some assumptions and did the assignments anyway and even created a succinct presentation to explain my process. I packaged and sent the files to the designated Dropbox and sent a confirmation email... then another asking when I should expect any word about next steps or if I wasn't a candidate anymore... nothing. At this point I cut my losses despite spending 10+ hours of work into it and check their socials and website from time to time to make sure my graphics haven't been used without my permission. Lessoned learned. Don't do work without compensation and Partners, do better.