What agency do I contact about my employer treating me like an employee instead of a contractor?

I worked for my employer for six years as a contract employee. they didn't pay any unemployment taxes. they didn't pay me over time, nor for any benefits which they were giving their employees. but they required me to come in at a certain time and to follow all of the employee rules. they even made me go to employee performance reviews. I finally left because they made me ask for a raise instead of letting me raise my contract rates. I want to know who I can talk to about these discrepancies.