Martin from GitHub here - love to understand what happened if you have the time to point me at more details. DM's open (martinwoodward on twitter and martinwoodward at github.com on email)
No recourse for such decisions unless you make a stink about it on an orange website or get enough likes on the website with the blue bird logo.
Furthermore, no: GitHub has a history of being bad at this kind of thing:
https://news.ycombinator.com/item?id=22593595
From the linked article: "A week after I’ve opened the support ticket, GitHub has finally replied. Suspiciously, this happened right after someone important has posted a link to this article on Hacker News"
https://news.ycombinator.com/item?id=22628961
Top comment: GitHub CEO coming in and apologising. From the linked tweet: "You sited US trade sanctions and sent me a non-descriptive email with no remediation information".