What happened before that ? Server wouldnt block someone unless he keep rejoining after getting kicked (either cuz of VPN/ban..etc) to avoid spam. The server will still automatically unblock you after 15 minutes. But, the server will block you again if you keep rejoining after getting kicked. So..
- If you were banned, make unban appeal and include along your ban ID (you can see in ban info message after you join the server). The admin that banned you will decide whether to unban you or not.
- If it's because of VPN detection, PM me your IP if you didnt use VPN and it's false detection.