Awww I am so sorry you are going through this, what an absolute nightmare! I can't believe the police aren't being more proactive in this case, especially considering the very recent and similar cases that have been in the news this week...these iditos are dangerous and they don't give a damn that they are bullying and victimising you.
I would definately be on to the police and explain how vulnerable you feel, I would also log all your interactions with the police and make a log of any harrassing behaviour from these idiots.
It is so sad that people can't live their lives in peace, without fear.