New ownership of a business won't honor a gift certificate worth $600 I had purchased from previous owners

Here's the deal. I had purchased a gift certificate from a spa in Costa Mesa, CA worth $600 for a friend back in Oct 2006. Since then, the spa had transfered new ownership. The new owners said that they will not honor the certificate because they are not responsible for the past owners liabilities. The company name is still the same just new owners. This is a service that I had paid for and is not being met. Now I wouldn't care if it was less than $100, but it is $600 freakin hard earned money that I gave as a gift to cheer up a friend. Is there any law in California that prevents this kind of stealing from consumers. Note, my purchase was on record, you would think that someone would inform any gift holder of the new ownership changes.