Welcome to FlyerTalk!

Any trading of any sort that does happen takes place on the Coupon Connection forum. You need to be a member for a while and have a number of posts to qualify for that. Until you reach that you will not have a venue for trading here.

And the information provided to you about the QF option wasn't particularly unhelpful, though you seemed to take it pretty badly.

If you are willing to consider the CNS option, note that the flight only operates a couple days/week. If you start by searching for flights to/from GUM and then GUM/CNS you should have somewhat better luck piecing a reward together that way.