👋🏻 Hello @jaemimoment, welcome to Figma Forum.
We don't currently offer support in Korean here, so I hope it's okay that I'm replying in English. I understand that this billing issue hasn't resolved it and I want to make sure this gets proper attention.
I'm not able to access billing or account details from this public space, but I've opened a case with our Product Support team so they can review the charges, confirm your plan status, and assist with the cancellation. Your case number is: 1997411, and they'll follow up at the email tied to your Figma account.
In the meantime, this resource walks through how to cancel your plan and covers the refund policy: Upgrade or downgrade your plan → Downgrade or cancel your plan.
If your school account should have qualified for the Education plan, this guide covers how verification works: Figma for Education → Verify your education status.
Please keep watch your inbox for the team's reply — and let us know if you have any trouble with moving forward with the Education plan verification.