Client: Can we meet at three?

Me: We scheduled the meeting for half past four. I’m out of town. If I try, I can be there at four but I can’t guarantee. I’m nowhere near enough to make it.

Client: But I have another meeting at four! 
Me: I’m sorry but if your other appointment called on such short notice, why did you agree?

Client: They called me a week ago.

Me: We had a meeting three days ago. Why didn’t you mention this then? 

Client: I didn’t think you’d have a problem with this!