@ajk you are giving reasons why you want to use dkk. Yes, you have a right to use dkk, if you have a danish based creditcard. That's what it's meant for
Your excuse, that ua let it go through anyway is stupid, it's like saying you are allowed to steal from a shop, since no one stopped you at the door walking out!
Forget about the why and ifs, did you fill out billing country as denmark? Was that the truth?
So you got a advantage, by lying
Is it according to law fraud?stealing? I don't know
But I can tell you, that its for sure not yashrus or midwar sheker dirchak.
We all lied and cheated the system here! You might not feel bad, because united deserves it, but don't fool yourself that its all kosher