Just one thing, we only hear one side of the story, and in every story there is two sides.
If all story was right, first of all, seller makes a mistake, and buyer want's the correct bag, seems fair. I think that would be some comms between both.
And please don't compare with a street shop, compare with a online shop, and they tell how sent back items.
And i know this illegal goods but if buyer shops to you, we believe you will provide the right item.