@Jonathan Safa, I'm a real estate attorney in Orange County, so welcome to Orange County! There is some decent information above, particularly the quotes from the California Department of Consumer Affairs and the text of certain Civil Code sections. Although I cannot comment on your specific situation, I will give you some further general guidance.
Generally, your options for repairs are repair and deduct, abandonment, or rent withholding. Note that rent withholding is only available for serious defects that violate the implied warranty of habitability and threaten your health or safety. You can get more info here: http://www.dca.ca.gov/publications/landlordbook/re....
Also, check the terms of your lease. Did the landlord warrant or represent that the gas in the unit was on? Working? In good working order?
I'm assuming that your gas utility provider is So Cal Gas. I've never heard of them taking so long to turn on the gas. Did you inform them that you are living in the unit and have no heat or hot water?
I hope that you're able to fix this soon. It hasn't really been cold enough for a heater yet, but I wouldn't want a cold shower.