Hi. I'm rather bad in English so try to type short;y and simply

Different products registered to different accounts. While I'm trying to register GC2TotA with account where was registered GC2 I'd get an error, so I create another account and with difficulty but register the game. So now I understand it was a mistake to register in this way and want to merge registration information about different games to one account. Please give me advise how I can do that. Can I delete account or information about registered product and re-register or something else? And if I can please tell me how? Thanks