If the spotify account is blocked, you will receive a notification email. Click the link in the email (as the screenshot follow), or directly visit the address: https://support.spotify.com/kr-en/contact-spotify-anonymous/:
Click "Start messaging". A small window will pop up in the lower right corner.
Enter your requirements in the small window, for example, "I received a message that my Spotify account was disabled.".
After that, you will be asked for some email information. When the message "will not engage in making unauthorized copies playable outside of Spotify" appears, reply Yes.
Wait for Spotify's review, if approved, you will receive an unblocking email within the next 24 hours.