Need Help.

I have a creepy neighbor who is listening in on our conversations in our home.8/24/14 it started. He had a guy hook up some kind of listening device. He pointed the long wire over to our home and has been listening in on our private conversations. I reported it to at & t and others but they have not caught him yet. He sits at his front window to listen in. Its always when he has the shade down. His whole family was there when it was installed. a guy in a orange older sports car (hubby thought a triumph) on the trunk was large white stripes with a black stripe in center. He is nothing but a trouble maker. Our home is up for sale to get away from the creep. Hope next buyer is the meanest ever. Is there anything I can buy to stop him from doing this ? If so where can I get it from? I am so tired of his illegal crap. Please help.