I can tell you for a 100% fact that just because you tell a doctor that you want a particular treatment, the doctor has no legal obligation to give you that treatment and the law will not force him to do so. He's the one who went to medical school, not you. He knows better than you do what is appropriate.
This applies to mental health doctors as well.
I cannot provide you with a website because there is not a website with laws that don't exist. There is not going to be a law giving a doctor permission to refuse to give you the treatment you wanted; it's because there is no law saying he has to treat you the way you want that means the doctor is on the right side of the law.
Two things I am tired of typing: 1.) A wrongful termination does not mean that you were fired for something you didn't do; it means that you were fired for a reason prohibited by law. 2.) The above answer, whatever it is, assumes that no legally binding contract or CBA expressly says otherwise. If it does, the terms of the contract apply.