[NJ] Am I being cheated out of overtime pay?

Hi folks. First time poster here hoping for some reputable advice. I work for a third-party automotive shop that takes AAA's contracts as a battery/service rep. My duties include testing batteries on-site and selling the member a new AAA battery if they would like, flat tires that members have which include major highways, unlocking people's cars, among other small duties. My current boss stops hourly pay from 9pm-11pm and any call in-between those hours he considers commission, which most of the time is shit and doesn't equal my hourly. I thought that was odd. Next, any hours worked overtime he either pays cash at my normal rate or logs it in payroll as commission, not hours. Every paycheck will never have more than 40 hours logged, yet I've worked overtime many times. I know there are exceptions for overtime, but what I need to know is am I exempt considering my duties?