People don’t seem to get that we don’t “buy” anything from the in-game MP, we “buy” the amount of in-game currency needed to “unlock” the in-game MP item.
It’s practically like micro transactions in a mobile game.
Don’t get me wrong though, I agree with the itemised statement of OP. It’s just that from a bureaucratic standpoint, we buy in-game currency, so that’s what’s on your receipt.
Edit: Only thing from a German perspective is, one could argue that the presentation of the MP with it’s actuall real-life currency and “buy” buttons are slightly misleading in what you actually buy. In germany you could probably raise a complaint with the german customer protection agency.
Edit2: From MS perspective it’s their way of saying: “You can get this from us, but we don’t take any legal responsibility for it, if it’s not working.”
At least, if you don’t want to go full “Karen Mode” on them.