Can't activate Online Pass for brand new copy of Dead Space 2 for PS3.

Try this: http://answers.ea.com/t5/Dead-Space-2/Dead-Space-2-CE-Online-Pass-Deactivated/m-p/818#M9

If you continue to have issues on PS3, attempt the following:

• Delete the Game Utility Data for your afflicted Game/Title. You can learn how to do this from Step 5 in this troubleshooting article.
• Insert your game disc and/or launch your game from the XMB. The game should inform you that your Pass is corrupt and give you the option to redownload your Pass.
• Simply re-download your Pass.

Source

Were you able to re-download the Pass?

No. It was never downloaded. I got this error message from the very start. It doesn't appear in my purchase history.

If you continue to have issues on PS3, attempt the following:

• Delete the Game Utility Data for your afflicted Game/Title. You can learn how to do this from Step 5 in this troubleshooting article.
• Insert your game disc and/or launch your game from the XMB. The game should inform you that your Pass is corrupt and give you the option to redownload your Pass.
• Simply re-download your Pass.

Source: http://help.ea.com/uk/article/how-to-re-download-your-online-pass/