If you are on benefits, there is no way you could afford a legal 'remedy' for slander.
You could report them to the Police for Harassment/Anti-Social behaviour.......and providing you are not breaking any rules as regards your benefits, you will just have to grit your teeth and put up with it. The DWP may well take some sort of action against your tormentor.
Ummm is right....go down to the Police Station and make a report in person, and keep notes of all your discussions with the Police and the Authorities.
Stand your ground with the Police, as they will probably not take you seriously the first time you make a report.
Make notes about every incident, when, where and what was said.