Linguistic or logical

This is a real dialogue which happened two days ago. I blame computer science.

Lady on the phone: "Sir, you will be paying the bill by cash or card or cheque?"
Me: "Yes."

Lady on the phone (repeats): "Sir, you will be paying the bill by cash or card or cheque?"
Me(again): "Yes."

Lady on the phone (repeats again, frustrated): "Sir, you will be paying the bill by cash or card or cheque?"
Me (realizing my folly): "Card."