I hear your pain, but seriously, they were probably calling the next person on their list when they found that someone cancelled an interview. Their interview has been full since I think August for months. Many many people who they were interested weren't interviewed becaues they had full interview schedule. They have thousands of app so I don't think they have to time to make it to their interview. If you say no, they will just call the next person on the list.Yeah, it's a little barbaric system, but that's what the market is like. See it this way, Let's say you get into Harvard the day before your NSU interview. Wouldn't you just call and cancel the interview? Now who is screwed?
I really don't think this says anything about NSU. Many many schools I am sure do this all the time. I only had positive experience at NSU. They are always there when I call, they answered all my questions, and I got my responses on time.