Since this is an extract batch, its almost impossible that your gravity was 1.082, unless you added a bunch more extract than was called for. I'm assuming you topped off a boil with water in the fermenter? If that's the case, its probably just a case of the boiled wort not getting mixed with the water, so when you went to pull a sample you pulled from the thick wort at the bottom before the water got mixed in, leading to a higher value. Don't worry about that, your gravity was probably right around 1.055 (again, assuming a lack of giant addition errors).
Now for the fermentation, do yourself a favor and pick up a 6-6.5 gal fermenter. You really need a lot of headspace, so its really difficult to get 5gal into a 5 gal fermenter. Especially with wheat yeasts, which like to build a huge krausen, you need that room for expansion so all the yeast doesn't leak out the top.
For this time, let it sit for another two weeks. It might be done a little before that, but there's no point in worrying about it now, as the yeast will continue to clean up after themselves. Did you make a yeast starter for your yeast? If you just used the Wyeast packet, you probably underpitched a little. Couple that with no oxygenation, and the yeast had a tough road to get started. If you got a blow-off and lost some yeast out the top of the carboy, that cut down on yeast levels as well. But more than likely there's still plenty of yeast in there, they just need a little more time to finish up.
Now if in 2 weeks its still sitting at 1.026, then there are a bunch of other options you can try (swirling, more yeast, etc.), but don't do any of that until you've given them a little more time. For what its worth, I'm a big fan of hefes, and actually just kegged one a week ago. Under-pitching probably helped to increase your ester fermentation (along with fermentation temp), so I'll bet it winds up being pretty tasty in the end!