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I'm sorry to hear about your situation. I assume that there's nothing in writing that guarantees you further employment for a specific period of time, and not working on those dates. The problem is that Labor and Industries would be correct here. You see, Washington 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.
So in short, unless you have a written employment contract or written employment policies that were explicitly violated AND you can show you have a property right in continued employment (which is VERY rare that someone could show that), I'm afraid to say that this is entirely legal. Unethical, immoral, and wrong, but still legal.
Now if (and hopefully it wouldn't get to this point) you were to be terminated, this is probably something that would not be for cause, and therefore you could still get unemployment. But as far as having a case against the employer for doing this, I'm sorry to say that at-will employment would control and you wouldn't have a case.
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. Please note that I don't get any credit for the time and effort that I spent on this answer unless and until you rate it positively (3 or more stars). Look for the stars on your screen (★★★★★). Thank you, ***** ***** luck to you!