Can my employee hold my final paycheck because they are angry that I am leaving?

I took an hourly position with a company and on my 3rd day we were told that hourly wasnt working and we were officially all commission only going forward. I never signed new paperwork but from that point forward I have been commission, Our hours are 10:00am till 6:30 pm I have to be at work by 10 because we have deals that start at 10am. We are not allowed to leave work until all of the new deals are done. I am at work sometimes until 9 or 10 pm and sometimes later to get the deals done and charged. They get angry with us if we make appointments for the next day because they want us taking new deals.. They say we should charge the deals the day we get them.. I have to work from open to close and i never know when close is. If we dont make our quota for the week we get a minimum of 400 for a 5 day week and if you miss one day and dont make your quota you loose 100 giving you only 300 for the week. We are told that we only get 5 days vacation for the year unpaid but that is used us when the owner takes her vacation and closes the business if you want to take yours another time you are denied vacation. I decided to change employers and when the person that quit before me went to tell them she was leaving and put in a notice she was told to just leave. I decided not to give a 2 week notice instead working until payroll was put in on wednesday for the previous week to make sure I got my last full paycheck and expecting her to keep my pay for the deals I closed on the 3 days I worked that week. I was told that if I dont come in they are going to stop pay on my paycheck so they will be keeping 8 days worth of pay from me.. Is there anything I can do about this? And am I really self employeed or is she just no wanting to have to pay for the insurance and things related to having hourly employees and then treating us like we are hourly?