You sound like you were an employer and that your employer violated the law. I recommend you speak to an experienced employment lawyer as soon as possible. Many of us, myself included, will provide a free consultation.
This answer is provided for informational purposes only and should not be relied on as legal advice. You should be aware that no attorney-client relationship is established through this answer and none will be established without a personal consultation and the signing of an engagement agreement.
I agree that you should contact an employment law attorney in your area. It does sound like you were an employee, and you and other employees like you should have received overtime compensation for the hours that you worked in excess of 40 each week. This is likely just one of a number of legal issues that you will want to discuss with a lawyer. Good luck!