I think the 'cancel' button only appears on your profile page while you are still within the window. I have a few days left and was planning on cancelling too. I did get some tickets this morning, though was foolish and waited to long decided if I wanted the set of 4 that popped up, so I ended up with 2 and 2. Would kinda like to try my luck with the general sale on saturday, but I'm slightly scared that then I would have 8 tickets and no one to take the others off my hands. Though, if the shows keep selling out like the first ones have, that might not happen.