First, sorry for any delay in getting back to you. I'm visiting relatives for Thanksgiving. I'm sorry that no other Expert picked up your question, as I thought someone would. I've opted back in.
Yes, it's conceivable that a viable argument could be made that the polices/procedures to which you agreed in writing formed the basis of a contract. It depends on how everything was written up.
If it looks like "you can't work here unless you agree to the following," and you did agree, in writing, then you may be able to argue successfully that the employer breached the contract by not bringing you back.
Where do you want to go from here? I can't make any individual recommendations for attorneys, but I can tell you that there is a very large law firm with offices in Tacoma and Seattle that took a leadership role in representing plaintiffs in some wage and hour cases (you know, those cases where people were required to appear for work 15 minutes before their shift started, but weren't being paid for the 15 minutes, etc...).
Often, people think that the large law firms just represent corporations, but actually many of them have the resources to represent a sole employee, like you.
If I may be of any further help, please write back. Give me a little extra time, because it's Thanksgiving week, and my time isn't quite my own.
Otherwise, please click "accept" so that JustAnswer and I can be paid.
Either way, Happy Thanksgiving to you and yours.