I'd also call the police, worth trying, or, like Jason mentioned, threaten to call the police.. And maybe adressing the owners of the house and talk to them, explaining that you don't want to be bothered might help..
We had this at our previous house. Kids kept throwing mud in our windows, throwing fireworks at the house, even continued their soccer game when the ball frew onto our backyard.. like what the fudge! But than my dad went to their parents and told them their behavior was just not from this world and that it kinda stopped..
So.. hope it gets better for you soon, good luck!