halo 4 tournament issues IMPORTANT

Someone who has the gamertag SWCC RECON prior to me, had register to the tournament before I did. And now I cannot register because my gamertag is registered under their windows ID, please help.

I don’t understand. If your gamertag is registered, if you play a Championship match, that will go towards your gamertag, which you obviously have access to because you’ve posted here and been playing.