My question involves business law in the state of: California
In giving my landlord my 6 month option to new notice.......they tell me that I owe 21,000 for employee parking that they undercharged me for the last 8 years. They said I was paying 50% of actual costs.

I told them I have paid all monthly statements (which includes rent and employee parking) on time, and it is now unfair for them to insist because had I'd know it was so costly, I would have allocated parking spots differently. They said I signed the separate parking agreement (which they signed also) in 2008 and I owe them. My attorney says in the agreement that they have the exclusive right to change the terms, and by paying the monthly statements I received on time I owe them nothing. He told me that they changed the terms each time they gave me a monthly statement.

My lease is up in 6 months but they want to meet with me now to discuss how I will pay them. Any helpful insights would be appreciated.gp2014