You were completely unable to cancel online before departure?
Well when IAH closed, I immediately knew to call the line (I'm only silver). I actually got someone to pick up immediately, but she said she couldn't cancel the itinerary because none of the flights were cancelled at the time. She could only rebook me for free (which wasn't acceptable).
By the time my flight was cancelled and I was rebooked, I tried calling in four times and each time I was met with a wait of 60 minutes+. This morning I tried calling thinking that the dust had maybe settled from yesterday, and it's still 25+ minutes.
I'll fill out the refund form. Thanks y'all :-)