Is coupon fraud an actual crime under CA criminal code

It sounds like you developed a scheme or system to defraud a retailer. As the other poster has suggested you should stop this conduct. You may never be pursued criminally but certainly it has bothered you enough to post it on-line.

You don't say whether you have been approached by anyone about this scam, or whether you are just starting to become worried about it coming back at you. In either event, my suggestion is to stop doing this. Your history of doing this MANY times would likely provide all the evidence they need to prove the intent to defraud. When you return an object (always without receipt, obviously) and receive the full retain price that you did not pay, you are making an implied false representation that you paid full price, and so they pay you that price when you return it. If you ARE being investigated, I would decline to answer any questions at all about this and see a lawyer ASAP.

This response does not constitute legal advice or establish an attorney-client relationship.

The retailer will be reimbursed for the $20. Coupons are like cash as an incentive to purchase their products.

Even with a receipt, you would get the full price unless they can return your coupon.