I am not licensed in NY. I would suggest this. I would first go to the Labor Board and report this company that did not pay you your sick leave and/or vacation time. Serious repercussions for failing to do so. Of course, these days who the hell knows if that still applies to companies. Look online for legal aid offices and see if they have a Self-Help section that have fill-in the blank forms.
Go online to Law Schools and there are often free help students in guiding you through research/filing forms and which courts or offices you can file a complaint with. Law schools are really an excellent resource for you as there are many non-jaded law students wanting to right the wrongs in the world. They are not licensed attorneys, but they are gold for help. I know, I used to help people for free all the time while I was in school. Hope this helps you out. Good luck, anon. Go fuck with those assholes. Also, if you have others you know in the same position from the company to join your fight all the better. A big group of people it will cause more of an impact. Remember, together you are stronger than divided.