Just as a general awareness, Rock Band World doesn't always have up-to-the-minute updates on Goals. I finished the goal the morning it came out, but RBWorld didn't update until later in the day.
Sitting there refreshing only hammers the browser and likely the servers, and if you aren't the only one doing it (which you wouldn't be since everybody playing this goal wants that code) you're only making it worse.
Also, the code doesn't show up in the Details. My code showed up in the description of the Goal when viewed in the "Completed Goals" section of the full list.