Just Another Frustration (JAF?)

Know what really really bothers me in almost any aspect of my life? When people don't do what is expected/their job/their responsibilities and then use up extra time in my life to finish said task.

So right now I'm on a call with a customer who I am handling as a courtesy for a co-worker on vacation. We have been discussing the same thing for 15 minutes, specifically documentation that has already been provided to them on API integration. They are asking me questions that I have answered by pointing the to the page number in the documentation.

I am literally being a table of contents reader/index reader here.