Is a business required to give cash back for gift certificate if asked?

[poppyblossoms]

I work in a small business. A customer recently came in with a gift certificate she received for X-Mas and asked for the money stating that by law I was required to do that for her. I told her our posted store policy (returns within 10 days of purchase for in store credit/exchange), told her that I knew nothing of that law and invited her to look it up and that I would do the same. Told her that we are constantly getting in new merchandise and that her gift certificate would never expire. When a person uses a gift certificate or a credit we will pay out cash when the balance is $5 or under. So, I'm wondering exactly what the law is.

Any idea?

Ive always felt that the certificate giver wanted to give the recipient an "experience" not just money. If they wanted to give cash they would have.
I don't know if it is important but I am in California.

thanks!