Yes, apart from being frustrating it's frightening. I'm sorry you have to face the situation where you can't feel safe in the place where you live.

Have you informed the Police? Do you have the strength for that? Sure, you may never see your money again, but a formal report gets tallied with others to create a picture that Police, urban, and business leaders have to pay attention to. Your report may contribute to pressure on the powers that be to increase policing of your area, or compel your landlords to tighten security or force them to ferret out the problematic tenants.

One thing you can do, if you've the energy, is be a squeaky wheel. You may get some grease.

Oh, and in the US there's that 2-1-1 / 211.org thing. They may have resources to help you, maybe...?