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I'm sorry to hear about your situation. Assuming that you don't have any written employment contract and they're not violating a clear written employment policy by their actions, they can do this. You see, Kentucky is an "at will" employment state. At-will employment means that without a contract, you have no contractual or other right to employment with the company. The company is entitled to fire you for any reason: a good reason, a poor reason, or no reason at all--as long as the company does not fire you for an illegal reason (race, gender, age, religion, etc...). But it extends beyond firing, to hiring, promotions, demotions, wage cuts and raises, disciplinary actions, and even scheduling. Unless you can show that this was done in violation of a contract, union agreement, or a clear violation of an unambiguous and binding clause against the employer, or that it was done because of some minority status (age, race, gender, religion, disability) that you have, then they do have this discretion.
In short, this means that the employer has a LOT of discretion. It can demand absolute loyalty, that you are only employed with them (even if you only work a few hours), that you quit any other job, etc... This is part of the at-will employment doctrine. So long as they're not discriminating based on race, age, religion, gender, or disability, they can do this.
I agree that it's unethical, immoral, and illogical, but it's not illegal.
I know this is probably not what you wanted to hear, but it is the law. I hope that clears things up anyway. If you have any other questions, please let me know. If not, and you have not yet, please rate my answer AND press the "submit" button, if applicable.
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Thank you, ***** ***** luck to you!