Ok. So, you are stating that you believe the basis for this discrimination to be gender and potentially sexual orientation too.
Let me start by telling you a little about employment law first, because you have some incorrect assumptions about what is actually allowed. You states "you cannot mess with people's livelihoods when they are doing nothing wrong" and also "you can't given someone up to six classes and then all of a sudden, they have nothing." Actually, both of these statements are false from a legal standpoint.
In employment law, unless you have an employment contract that specifically states that you can only be terminated for cause, your employment is "at will." At will employees can legally be terminated at any time, with or without cause. The employer doesn't need a good reason. Legally, they don't even need a reason. They can absolutely mess with people's livelihood, even if that person is doing nothing wrong. That, by itself, is not illegal at all.
The ONLY way this situation becomes illegal is if the employer is making the decision based on an illegal factor, such as race, religion, gender, age, disability or recent FMLA use. If you believe one of these was the basis for their decision, then you have to file an Equal Employment Opportunity Commission complaint in your state. That government agency can investigate the situation and issue you a right to sue letter based on the results. You have at least a gender and age argument that you can make here, but again, your focus has to be on those illegal factors. You do not need an attorney to file this EEOC complaint, so that is your first step.