CA state landlord tenant law, tenant's right to break lease upon landlord's request for tenant to obtain co-signer

My lease: I signed a lease and I was told that my financial aid letter will be my co-signer. A few days later I was told that my letter wasn't a enough. I was told to bring two paycheck stubs. A week later I brought two paycheck stubs. They said, "it's not enough." I thought they will break the lease. they are saying that they don't have break cause in the lease. They afre saying that i need a co-signer. I don't have one. I am wondering what can I do to break my lease?