Lineage II - South-East Asia (L2-SEA)

Go to www.lineage2.com.sg and click the My Account button
Click on the Register button to register your account
Enter the CBT code printed in the CBT card included in the invitation kit, then click Submit
Fill up the registration form (IMPORTANT! Be sure you have your ACTIVE mobile phone when you register. An authentication code will be sent to your mobile to complete registration. You will also need to input the registered mobile number during game-time card loading)
Enter the authentication code on the webpage and click Submit
You have SUCCESSFULLY ACTIVATED your Lineage II South-East Asia (L2-SEA) account
To play the entire duration of the CBT, click on Load Game-Time button and log-in to your account
Click on the Load Game-Time Now button, enter your Login Name and Mobile Number, and click Submit
Enter the Card # and Pin # provided in the CBT card, then click Submit

CBT Code: SHER-23JC (sample only) - 8-digit alphanumeric code
Game-Time Card #: BBY0723F-178240 (sample only) - 14-digit alphanumeric code
Game-Time Card Pin #: JC23-HART8-EV0L (sample only) - 12-digit alphanumeric code

All Closed Beta Test accounts will be wiped out at the end of the CBT period. You need to register for a new account during the Open Beta Test.
The enclosed "Game-Time Card" is valid only during the Closed Beta Test period. You cannot sell or transfer the game-time card for use on another account.
By signing up for the Closed Beta Test, testers agree to participate in any activities/discussions pertaining to Lineage II when requested.

via Petition

File a petition in-game by typing /GM in the chat box.
Wait for a GM to assist you.
Although you can use the Petition System to report bugs, we recommend that you file a report in the Game Support website (support.lineage2.com.sg) so that we will have a more detailed account of what happened.