You might find that part way through a Quest you are no longer interested in completing it.
Once again, travel to /warp Quests and right click the Quest Master
You will be met with the Quest menu:
From there, select the Gold Ingot, doing so will open this menu:
You will see the icon of the quest you are actively participating in, selecting this icon will open the confirmation menu:
Select the Green Wool, and this will cancel your quest