It's a no win situation from what you've told us. You don't want to confront them. You don't want to report them. And they don't seem inclined to change. If it's that much of a pain I'd suggest moving on. Find a new spot. You're letting two yahoos ruin your hunting and dominate your life. If they were in the pen at sometime, it's quite possible they're not even suppose to be near a firearm. Move on.