A large taser, like this one
www.google.com/imgres
works quite well for me in the queue at Woolworth's!
Seriously Bluetjie,
for starters you'd better move to a better area, should help.
Then, be in a house so that a single scream for HELP will have troops storming in, both help & a deterrent. A remote triggering a siren will also work but then have several mounted in the room.
Lastly, a small pepperspray works wonders, but do keep in mind that the second you use it you make for the door... as this stuff will also affect you yourself. You hide this gadget, always, never ever show it unless you will use it!
If you promise you'll get a sjambok I'll visit and show you how a bloke will take this from you in under a second... size does matter remember? He then will have a field day using it on you, not a good idea.