the only serial i found in my box besides the trial serials for other games and the 14 day lineage trial, was the one insinde the game time card. my question is was there any other serial in the box when you opened it? if so, where was it. i entered the code on the game card and i think it just gave me the 15 days free. i wanted to get the mask on an existing account so i followed the directions in the sticky about it. i never got the choose character part, so that leads me to believe i'm missing a serial.
1 Called Game Time Card/Code
1 Called Security Code - It is a new Serucal Number for the Game with upgrading the old account you get 1 month of game time and a button to add the mask.
There is also a set of Trial accounts for l2, autoasault ... they are not involved into the mask thing :-)
The code that adds thirty days of game time also adds the in-game item to the account. It sounds like you did add the 15 day code instead. Please try the other one, and if you still don't see an option to choose a character, please contact the team through the web site (http://support.lineage2.com). Thanks!