Legal Question in Landlord & Tenant Law in California

You might put this information in writing, send a certified return receipt letter to the property management company and, if you know who it is, the landlord and request proof of their having notified you of the rent increase eight months earlier. If they can't adequately provide that information, write back and inform them that the information provided is inadequate, but you'll start paying the increase now. If that becomes a major issue though, you might want to negotiate a compromise.