Just encountered some lying customer today. I can't exactly explain

Me: "Thank you for calling Technical Support..."
Customer: "Hi, I have this PDA unit..."
Me: "Okay, what seem to be the problem?"
Customer: "I have this problem with the reddish on the font when I'm selecting..."
Me: "Hmm, seem to be a ClearType font and it has something to do with the resolution..."
Customer: "Eh, don't bullshit me lar. I'm a technical person myself and I know this has nothing to do with that."

What a load of crap! I had the unit in front of me and when we disable the thing, it resolved the problem immediately. And this idiot dare to say he's a technical person. I suspect that this idiot is trying to swindle a new unit. And this idiot actually have the nerve to say I'm bullshitting him. I know by the tone of his voice that this idiot is a liar and from the troubleshooting step it states that customer should be seeing the samething.

Me: "Are you sure? Because I have a unit here that says otherwise."
Customer: "Okay, then what should I do?"
Me: "Just disable the ClearType font."
Customer: "I disabled it and it doesn't work."

And he twisted his words just like that. We know this is a trait of a liar.

Me: "Are you sure you've disabled the ClearType?"
Customer: "Yes I did. And I never have that problem with iPaqs!"

Here customer comes telling us on how other brands are better than ours. I got a friend working in Compaq and he said there are just as much customer reporting that our brands are better than theirs when they're talking to them.

Oh crap, this bloody Singaporean idiot just ruined my beautiful day.