I see. Thank you for clarifying that for me, John.
Under CA law, it is typically unlawful for an employer to retaliate against an employee for asserting a legal right and challenging an employer's classification of an employee as an independent contractor in good faith would normally provide such protection against retaliation. Since you did so in a phone call, it may be more difficult to prove that you made the complaint, but if you can, there would typically be recourse against the employer for taking adverse action against you.
It would be best to retain a local attorney to represent you in this matter, either communicating a demand to the employer and attempting to resolve the situation and restore you to your long held position, or to file suit seeking damages for unlawful retaliation.
Here is a link which discusses this type of legal claim against employers:
You may also wish to file a complaint with the state labor board which will trigger an investigation as to whether you actually are misclassified as an IC and may result in the payment of back wages if appropriate.
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