Cancelled the class

Yesterday I wrote that I went to the college and got signed up for a class and today when I got home from work my sister in law told me that the college called and said that they cancelled the class I was enrolled in. I am upset because now I have to find for a replacement or just wait for the fall semester. I tried to call the phone number that they left for me to call but nobody was there to answer the phone. I think I need to go to the school again and ask them why they canceled the class that I wanted to take. It is a good thing that I did not buy the text book yesterday or else I have to return it too.