Curious, do you see this any differently than buying a multi-pack of something on Amazon when you know they'll only ship one?
1. I meant that tongue in cheek
2. I don't condone that at all. Buying something that you know will be one of an item and then calling them up saying you were expecting 10 and only got one is a total lie and using that to now get them to give you money is at the very least dishonest and gnievas daas. Very possibly actual stealing.
ETA: I know that there are many here who do not agree with this assessment. Note that I was not the one who brought this up but rather was answering a question addressed to me.