How about....

"My new computer isn't working right, I think the foot pedal is broken."
"Foot Pedal Ma'am? I think you'll find that's the mouse"

Or...

"My TV's got no picture"
"Are there any lights on on the front of the TV?"
"No."
"Can you check the power plug to make sure it's connected?"
"I can't see behind the TV it's so dark."
"Can you turn on a light?"
"Sorry but the power's out.... Maybe I have a flashlight...?"

Or...

"What's this "design hours" charge for? I didn't ask for that."

Or

"That's OK, I don't need you to be licensed, is there a discount if we don't use that?"

aah Good times...