The California Department of Consumer Affairs publishes a great book called, "California Tenants- A Guide to Residential Tenants' and Landlords' Rights and Responsibilities. It should cover your issue. Also read your entire lease agreement and all the details. You can view or downloand this publication from their site at http://www.dca.ca.gov
Marcie Sands, REALTOR
Simply The Best Real Estate Company, Inc.
I hope that this helps, you may need to consult an attorney if the landlords persists. I have posted a link to the Lawyer Referral Service in North San Diego.