Legal Question in Employment Law in California

There are no laws against 'unfair treatment' or poor management. In general, unless an employee is civil service, in a union, or has a written employment contract, they are an 'at will' employee that can be disciplined or fired any time for any reason, with or without ‘cause’, explanation or notice, other than for illegal discrimination, harassment or retaliation under the ADA disability, Civil Rights [age, race, sex, ethnic, religion, pregnancy, etc], Whistle-blower, or similar statutes. The employee's goal should be to keep the employer happy and make the company money. That’s how they pay your wages. Now if the firing was illegal under those definitions, feel free to contact me for the legal help you’ll need..

Sure you can sue them, and waste your time, and then lose. You have no right to employment when there is someone better out there.