You know, I bet when you said 'why have you got this' he thought you were saying 'you stupid fool - didn't you know your cc was out of date. Let me sort this out, you moron.' And the rest of the conversation was his revenge. Yes, I know you weren't saying that, but I would bet that's what he heard. I have read you shouldn't say to kids 'why did you do that' as it pretty much invariably sounds like criticism.
Not defending him winding you up, mind, just trying to suggest why he was doing it. Hurt male pride - you'd caught him out.