I clicked and earned credits, why didn't my "credits owed" go up?...

Keep in mind that your links are constantly being displayed throughout the TrafficSwarm network. So for example, if you click and earn 3 credits but notice that your Credits Owed only went up by 2, that means that your link was displayed once in the time it took you to reload the page. Your stats would confirm this, and always show you exactly what is happening with your credits.