First of all, Charlie was exploited and discriminated against by his friends. He was beaten up by his "friends" for being different. Charlie was also exploited by his "friends" when they made fun of him behind his back. Most of all, he was treated unfairly. Charlie's "friends" did not seem like real friends, because they treated him poorly.
Also, Charlie was exploited and discriminated against by doctors. For example, one doctor exploited Charlie