There is a issue where some consumers who are purchasing MLB ’12 and redeeming the online pass which is giving MLB ’13 access incorrectly. Please know we are working on this issue.
Once we have an update; we'll inform everyone what the solution is in this space. You're welcome to subscribe to this thread and get email updates when an SCEA rep replies.
This has now been fixed so the users should see the MLB12 Online pass when redeeming codes.