Board Thread:The Quarters - Q & A/@comment-24.19.158.83-20141026194754/@comment-24150802-20141030095759

Click on the reward as if you wanted to use that reward. Does that make the megaphon icon change to a broken megaphone or a trash can? If so, you should then be able to delete it.

You can restore the gold that you waste by doing this at Settings -> Site -> Fix Character Values.