A small online store selling physical goods has failed to ship a purchased item within estimated timeframe and has agreed to refund (under $2,000).

However, it is now taking time to process the refund, again, giving an estimation of several weeks (or say months). Like it did not ship the item, there is little hope that it will process the refund either before it goes bust.

Credit card chargebacks aside, are there any legal means to forcibly extract the refund from them sooner than several weeks/months?

Since the store does not dispute owing money, would it even make sense to file a Small Claims case? To proceed straight to enforcement? How difficult would it be in California?

Any consumer protection agencies (threatening to) complaining to which would motivate such a store to process refund quickly? The complaint would be not only about taking time to process the refund, but also about the store still showing the item as available in stock and fooling other customers.