Many of the discrimination statutes have a minimum number of employees the employer must have before they can be sued. With the ADA, for instance, it is 15 employees working at your office or within a certain distance.
I'm going to ignore those numbers for right now but just remember it could be an issue.
Obviously, they could be sued for discrimination against someone with a disability under the ADA. Their argument that you could be fired because you didn't tell them isn't viable because they couldn't have not hired you because you have a disability.
You can also sue them under the Fair Labor Standards Act for not paying you correctly. You can't sue them for paying you under the table but just be sure that you report that income on your tax return. If you already filed your tax return and didn't declare it then talk to an accountant about amending your return.
There is also a breach of oral contract theory, again based on them not paying you. That is just another way of getting the pay but it is a cause of action you would want to assert in case they claim you aren't covered by the FLSA for some reason.
You definitely want a lawyer to help you with this because it will be complicated. You can find a lawyer by going to www.lawyers.com and in the section for Area of Practice enter Civil Litigation or Employment Law. Either of those will have the skill set you need.
You also need to talk to them about filing a Charge of DIscrimination through the EEOC. Filing with the EEOC is absolutely required before you are allowed to file a discrimination case and if you don't file with them then your case will be dismissed. You have a limited number of days to file, as short as 180, so you want to talk to the lawyer ASAP and see if they want to assist you in filling out the paperwork but even if you can't find a lawyer right away contact your local EEOC office, you can find the nearest one through their website at www.eeoc.gov, an file the charge so you don't miss the time limit.
Those are the only causes of action that are obvious from the facts although others may develop later depending on what they tell and send to the EEOC during the investigation.
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