I am so mad at my boss right now. I'm practically a wage slave...I've been working at least 10 years in my industry, and someone less experienced than me got a promotion.
Wage slavery is used to criticize labor explotation
Yeah, and I'm definitely being exploited at my current job. I work 60-hour weeks, and I haven't had a decent raise in 4 years. 
It generally means that there is an unequal balance of power between the labor and the business owners.  Sounds like that applies in your situation
Yup, pretty much sounds on point. They need to do something to stop stuff like this from happening.
They might be violating US Labor Law.  It oversees to the rights of employees in the United States