California law states that a landlord can enter a rental unit only for the following reasons:
-- In an emergency.
-- When the tenant has moved out or has abandoned the rental unit.
-- To make necessary or agreed-upon repairs, decorations, alterations, or other improvements.
-- To show the rental unit to prospective tenants, purchasers, or lenders, to provide entry to contractors or workers who are to perform work on the unit, or to conduct an initial inspection before the end of the tenancy (see Initial Inspection sidebar).
If a court order permits the landlord to enter.
-- If the tenant has a waterbed, to inspect the installation of the waterbed when the installation has been completed, and periodically after that to assure that the installation meets the law's requirements.
The landlord or the landlord's agent must give the tenant reasonable advance notice in writing before entering the rental unit, and can enter only during normal business hours (generally, 8 a.m. to 5 p.m. on weekdays). The notice must state the date, approximate time and purpose of entry. (Civil Code Section 1954(b),(d)(1).)
However, advance written notice is not required under any of the following circumstances:
-- To respond to an emergency.
-- The tenant has moved out or has abandoned the rental unit.
-- The tenant is present and consents to the entry at the time of entry.
-- The tenant and landlord have agreed that the landlord will make repairs or supply services, and have agreed orally that the landlord may enter to make the repairs or supply the services. The agreement must include the date and approximate time of entry, which must be within one week of the oral agreement.
Landlord can only enter under conditions above. Therefore, you could have called the police for tresspass. You could sue your landlord in civil court for tresspass, maybe harassment, breach of your rental contract, i.e. quiet enjoyment, constructive eviction, etc. Long story short, the potential recovery is probably not owrth the hassle. Nonetheless, if what you're saying is acurate, I think you have grounds to terminate your lease and move.