Since your investigation into where the proceeds would go was a cursory one at best, you've no right to complain. You could have chosen to wait until the name of the proceeds recipient was made public. Instead, you chose to go ahead and buy the essay before you were sure of any profit recipient.
You're only now coming to this conclusion about Mr. King? I find it interesting that an essay regarding the use of guns in the U.S. is evidence enough for you and not any of his previous writings, written or recorded interviews, or recorded lectures and/or appearances.