The flight originated and was sold in Korea, so I'd be covered by Korean protection laws, which state this.
Link to the Korean law in English
But this is what I'd be invoking
Article 119-2 (Protection, etc. of Air Transport Users)
(1) Each air transport service provider shall formulate procedures for damage compensation and its execution plan to protect air transport users from the any of the following damage (hereinafter referred to as “damage compensation plan”): Provided, That this shall not apply where the air transport service provider proves that such damage arises from an event of force majeure, such as meteorological conditions, aircraft rotation, unscheduled maintenance for ensuring safe operation, and natural disasters that occur during the operation of airports: <Amended by Act No. 11690, Mar. 23, 2013>
1. Failure or delay of transportation by the air transport service provider;
Basically they said I called and changed it when I didn't, but I'll share what I posted to twitter.
My plan is currently to take them to small claims court in Korea (I'm currently a resident there). Korea consumer travel protections are pretty stiff, so I don't think I'd have much trouble winning especially if the call records are subpoenaed. I have submitted the contact form for customer relations, but they say 7-14 business days to get back to me and I'm buying a new flight to go back already.