I'm becoming increasingly frightened due to (what are clearly) drug addicts knocking for a dealer who used to live in the property. They are always desperate and off their face so not easy to deter.
This happens all day, one was as early as 7am and one as late a 2:30am 
They knock on the windows, flick and shout through the letter box and bang loudly.
I have two babies and mental health struggles I'm genuinely terrified. If I answer and say they dont live here anymore they ask if I know where they are, where other dealers may be, if I know "insert endless amount of names" and where they live.
I don't. I don't know anything at all, I just want left alone. Really though, other than moving which isn't an option.... Is there anything at all I could even do?