I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear about your situation.
There is no specific law that prohibits a landlord from renting an apartment without showing first, as long as he can find a willing tenant who doesn't mind renting it sight unseen. It's up to the tenant to ensure that the apartment is up to their standards before signing a lease. The same is true of the rent - if you agreed to pay more than the price stated in the ad, that's allowed. Rent is one of the things to be negotiated before signing a lease.
With that said, there are certain things the landlord is required to do. The property must be fit for human habitation: no holes in the floors, walls, or ceilings, at least one working bathroom, no exposed electrical wiring, locks on the exterior doors, free of rodents and pests when you move in, and things like that. If the property is unliveable, you can call the city to come out and do an inspection, or you can send the landlord a written notice of his obligations under Cal. Civ. Code, Section 1941.1 and a demand that he make repairs immediately.
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