Cylinder order

A man showed up at my door today with a slip of paper saying I'd ordered a new cooking gas cylinder.
No, I hadn't.
He had the right address, right floor, landlord's name--but no, I hadn't ordered a cylinder.
I told him I didn't need it. I hadn't order it.
But yet, there was his piece of paper that said I did.
The cleaning lady who was in my house at the time, assured the man that, no, I didn't need a new cylinder, I still had gas.
And finally, he went away.
Then the cleaning lady laughed and said, "Why would you need a new cylinder? Where would your gas have gone? You never cook anything."
Smart aleck.