Five magic words.
Of course, you have to say it firmly, in a tone that says, "This is not up for negotiation." And, of course, you have to be demanding something reasonable and clearly within your rights. It also helps that you have a ticket that's been ignored for two weeks.
In this case, I reiterated what I already said when I first called on Thursday -- that I simply wanted my account downgraded so that they could cancel that $72 charge for a year of premium membership, which prevented me from accessing my account. Then I said those five magic words, and then paused.
It feels good to be Opal again.
/me downgraded; therefore, I exist.