I've had a similar experience at work.

It was actually a colleague of mine speaking to a user whilst we were trying to replace their old software with our new stuff.
There was a button called "Batch Match" and my colleague wanted to find out what it did...

Him: What does the batch match button do?
User: When you press it it creates a batch match.
Him: Yes but what is a batch match?
User: It's when you create a batch match by pressing the batch match button.
Him: OK, but what does it actually create?
User: It creates a batch match when you press on the button and it opens up a batch match.
... and so on.

In the end he gave up I think.