Oh, madam, what can I do for you?
I'm sorry to say the bill you sent me was incorrect.
Incorrect, madam? That's very strange.
Yes, I know. And what's more, this isn't the first time.
Really, madam? I find it very hard to believe.
Look. It's happened 5 or 6 times in the past 3 months.
Ah, well, I must apologize, madam. It's the new computer.
Well, don't you think it's about time you got it working properly? It's most inconvenient.