When I was a retail manager, this happened all the time. Most often, a product was no longer available but they hadn’t informed us at the stores or we had an outdated catalog. Generally, I would call the customer and see if there was an alternate product that we could order instead of just leaving them with nothing.

If you have to special order it, there is a reason the store doesn’t carry it as usual merchandise: low demand, hard to get, at the end of the manufacturing cycle, etc. They do not need your consent to cancel the order if they can’t get the item. If the order can’t be fulfilled in a timely manner or can’t be fulfilled at all, they have an obligation to cancel it and return your money. TaxGurl