If you're in the US, you were actually an employee (not a contractor), and this is about unpaid wages, you might be better off contacting your state "workforce

If you're in the US, you were actually an employee (not a contractor), and this is about unpaid wages, you might be better off contacting your state "workforce services" or whatever whatever agency handles employee-rights violations. Obviously this is going to depend on the state, but they are typically pretty aggressive about going after employers that try to pull shit.