Legal Question in Real Estate Law in California

That's a form of retaliation and prohibited under California laws -- see Civil Code Sections 1940 through 1945 which should be insightful. A good approach in this situation is to document your original complaint along with your subsequent complaints and then address the minor repair issues by "repair and deduct" -- i.e., give notice to the landlord that it needs to be fixed, that you believe the landlord is not repairing because of past valid complaints and that it is retaliatory, that if and after 30 days the problem is not fixed you will repair the problem yourself and deduct it from your rental obligation. Then do it. Hope that was helpful and good luck.