Who should I contact about the company’s irrational policies?

I work as a sales representative for the last 4 years in a commission plus hourly wage. For the last year, my employer has set up many rules that my department has to obey or else we get written warnings. After 4 warnings, our commission gets reduced by a fourth and after more than 5, we can get terminated. The reasons for these warnings can be for anything like coming in to work at 9:01 instead of 9, taking a 29 or 31 minute lunch instead of a 30 minute lunch, not emailing people on time and literally anything. We have meetings every day that change company policies and where they verbally threaten termination for everyone. I honestly feel harassed and have so much stress that I've been seeing a doctor about it because I've gotten physically ill over it. Having that said and done, I'm sure none of that is illegal. So here are a few things I feel are off: I've noticed that pay for Chinese employees are considerably larger than non-Chinese. If we ask for a raise, they just tell us to sell more. Non-Chinese employees get minimum wage while all Chinese employees are salary based which I feel is incredible wrong. We also go to a convention every year 2 times a year where we are paid $400 extra to attend but we do not get paid for the 8 hours it takes us to travel to and from the convention. We also have to attend 2 days in which we work for about 14 hours that are not paid. The $400 are supposed to cover the 8 hours traveled plus the extra hours paid plus cover our meals for 5 days. The company requires us to all share rooms. If you want your own room they deduct it from your paycheck. Everyone usually gets their own room because it’s uncomfortable to sleep with someone else. They also rent us a car but if our schedule doesn't meet with the departure time, we have to get our own means of transportation and pay out of pocket for any gas. I'm not sure if any of that is illegal or not.