Yes, you are not understanding how it works. All you need to do is select the head to head quick match option and let it find an opponent for you automatically. Those are RANKED. I've done that since release and all my games are ranked and I can go view my leaderboards anytime and see the result of my last game and my record.
The reason it will always show unranked in those custom matches is that you are not allowed to make a custom match and have it ranked. If you were, you could play with friends who would lose to you on purpose, etc.
Why no one can answer you here is beyond belief. It is a simple thing.
