Revive my expired education plan

Hello,

My name is Yeseok Jeon and I’m an assistant professor at Ulsan National Institute of Science and Technology (UNIST).
My github account is jys0710 (email: ysjeon@unist.ac.kr or jys0710@gmail.com).
I also lead S2 research group. However, yesterday, our research lab’s GitHub repository (S2-Lab · GitHub) education supporting (team level service) is expired.
Although I tried to revive it, I cannot find any related options.
For example, if I try to revive our git repo through “github-org-upgrades” page, this page just said that “coupon already applied”.

If you don’t mind, could you please help me to address this issue?