被房東騙，錢可以不付嗎？

I am in California.

My lease is expired in the middle of July. I bought a house and wanted to move out early.

Since the townhouse I rent is fairly easy to be rented out, (It has good location and a good school nearby,  also quiet.)  I think I can save some money if somebody can rent the townhouse immediately after me.

I notified the office in May. After few days, the lady in the office told me my unit is rented out.

I moved out and turned in keys in the middle of June after I paid all my prorates in June. (I received a letter from the office told me how much I need to pay before I moved out.)

I thought all is over and had happily lived  in my new house for two days until I received a call from the office manager saying I owe them rent till to the middle of the July, also $1200 discount they give to me, since I signed a lease agreed to pay back this amount if the lease is broke or I move out early. Also I was told that the new tenant will move in on July 2. I was outrages because I was misled and nobody tell me anything before I left. I could have avoid paying $1200. I immediately asked my keys back but was refused.


We came to the office several days later, asked if we can avoid that $1200. The manager is not there. The lady said, "The new tenant changed mind, He(She)will move in after your lease is expired.In that case, you don't need to pay $1200." Also, she asked us to talk to the manager. We did not talk to the manager because we think at least we don't need to pay that $1200.

Now we received a letter from office asking the rest of the rent plus $1200 concession because we break the lease.
Obviously that lady lied again. I have to pay the rest of the rent, but I refuse to pay the concession money.

Do I need to go to the small amount court on this dispute, and if so, will I win?