School wont let me take AP exam without course?? :[?

The reason behind not letting you take the AP exam when you did not take the course is because there is not point in taking the AP exam. If you're only using a review book to study for this exam, then you won't be as proficient as someone who takes the course, reviews the material already covered with an AP review book, and taking the AP exam or someone who took the class in college. Skipping it in college will not be worth it since you did not cover the material for a long enough time to be able to understand it fully through long term memorization