Thank you for your question. I look forward to working with you to provide you the information you are seeking for educational purposes only.
I am a different contributor.
As your previous contributor stated, this is not an open and shut case. Also, just because you know someone who got $20,000 allegedly because the landlord did not reply to an email, there are likely many more facts in that situation that are not being told.
Now, as far as your claim, your previous expert was correct in that one of your claims against the landlord would be based on coercion/undue influence. In addition, you can actually argue this was a bait and switch (suckering you in at one rent and at the last minute when you could not change they added more to the rent) and that could fall under the CA Consumer Protection Unfair and Deceptive Practices Act.
Your first recourse is filing a complaint with the CA Attorney General consumer protection unit, since they have the power to enforce unfair trade practices. Second, you could indeed sue the landlord if you can prove the unfair and deceptive practices (bait and switch) and can seek punitive damages
(which can be up to 3 times your actual losses) and also attorney's fees.
So you can go to a local consumer protection law attorney to begin pursuing this case, but before you do so I would file a complaint with the Attorney General and also send the landlord a letter informing them that their practice was an unfair and deceptive practice and add up all of your actual losses and make a demand that they reimburse you for those losses or you will pursue legal action (this is known as giving them a right to cure).