I would speak with an attorney. This is very odd sounding. You went to closing and were not given keys. Did they tell you they were not moving out. The whole situation seems absurd. Ask your agent to refer you to a good attorney.
REALTORÂ® | Mortgage Broker
Keller Williams Realty | 360 Lending Group
o 512.669.5599 m 512.633.4157
Have him evicted for trespassing?? No, seriously-- I don't know what the California laws are or what the agreement was when you closed on the property. Best to consult with an attorney... contact your real estate agent (if you have one) and he/she can recommend an attorney.