Unfortunately, there is an extremely malicious spammer who continues to post fake questions in the Q&A of our Udemy courses. Since the whole point of selling a Udemy course was to deliver personal service via the Q&A, it is not right to continue to sell the courses. The Matrix Algebra course is still for sale, as it is Udemy for Business. I sent an email asking for it to be unpublished, and I would expect that to take about a week or so. I will not be returning to Udemy or any other platforms.