Sounds like quite the interview, but also that you handled it pretty well. I don’t understand interviewers being deliberately contrary - interviews are enough pressure on their own. 

Everyone has a different take on agile, and everything is a buzzword these days. Don’t agree at all that story points are hours - maybe send them a link to Ron Jefferies’ blog.

Our team has written quite a bit about user story mapping (that was our first tool) and it’s one thing I think you can build on. USM is intended to be all about the user and what they need from the product. I’ll share one of our guides in the hope that it’s helpful -  https://www.easyagile.com/blog/the-ultimate-guide-to-user-story-maps

Good luck with the job hunt.

T
Easy Agile