@mrkokee
If you played any EA game online before linking your PSN ID, then it created its own and linked it. You have two options at hand, and both require you to get in contact with an EA Game Adviser.
You can ask them to find out the e-mail it is linked to, and then sign into your companion app with that e-mail.
Or you can ask them to UNLINK the PSN ID from the other account (they will have you play a demo or something to verify it is your account) and then they can unlink it. However, during an unlink, you will lose ALL progress from every EA game linked to the PSN ID. After it is unlinked, then you can do the normal steps and link it to your account.
I would personally advise the first of the two options, unless you dont have much progress on any online EA games. I did the second because the only other game I played was NFS: Hot Pursuit on my PS3 a long time ago, and had not started playing Battlefront yet, so I didn't have much to lose, so I took that route. But if you have alot of progress on Battlefront or other games, I would do the first option.