Thank you for the information and your question. Whether you have any special rights in relation to this issue depends entirely on whether you have a contract (like a union bargaining agreement) or written policy that gives you any right to appeal or grieve this decision. In other words, under California employment law in general, if you are an "at will" employee, which most are, you have no rights to appeal or grieve a decision like this since an employer has a right to make this and termination decisions for any, or no, reason and with no notice or warning. The only exception to that absolute right is a contract that states differently, as mentioned above, and also that they cannot make their decisions solely motivated by your gender, race, national origin, age (over 40), disability, religion, pregnancy or military service.
If your situation does fall within one of the exceptions I mentioned, then you can file a complaint with your HR department if you believe you were targeted because of your status in a protected class. If they do not resolve the issue, then you will need to seek legal counsel with an employment attorney and will also need to file a discrimination complaint with the State or the EEOC.
Please feel free to ask for clarification if needed. If none is needed, then if you could take a moment to leave a positive rating in the box above, I will receive credit for assisting you today. Thank you.