Idea Grove interview questions

I applied to multiple positions at Idea Grove and only got a call for the SM Internship. I went through a phone interview, quick and easy. Then was given an assessment which consisted of creating 8 different social posts (graphics and captions) and replying to about 10 “comments” that a client could receive. I was given 5 days to complete it and took the whole 5 days, and when it was finished, it was 8 pages long. I think that is a bit too much work for an internship position. I then had my second interview with two people, it was a little over an hour, then told me they would look over my assessment and make a decision if I advanced to the 90 minute culture interview. It was a long process and I dedicated a lot of my time for this process, yet did not advance because my assessment had some grammar errors. They told me they wish I had spent more time on my assessment because of the few grammar errors and that kind of felt like a slap in the face because I truly worked hard on it because I was extremely excited and eager about the opportunity. The people I spoke with were nice and helpful throughout the process, so I wish I could have had the opportunity to prove myself further to be a part of Idea Grove, which they spoke highly of.