Precisely. It's bad practice on the part of the retailer, and if I were in their shoes I'd refund the customer immediately as a gesture of goodwill. That said,

Precisely. It's bad practice on the part of the retailer, and if I were in their shoes I'd refund the customer immediately as a gesture of goodwill. That said, it does not appear to be malicious, and ultimately the customer bears some responsibility for submitting their order without checking it.