When you add a number to your spam block list, what message does the blocked caller hear when they attempt contact? Are they informed that they are blocked? Or do they get a standard "this number is disconnected..." type message?
"You have been blocked" or "leave me alone". Just kidding. I tested this with a friend and they state they are receiving a fast busy when calling my number. I would think that the person would receive some sort of recording. Maybe the message or lack thereof is based on the switch where your number is located.