It downloaded (installed) your EPs or it's just showing them as available for download because they were registered to your account? I've never seen EPs or other games download and install all on their own. Unless there is a command or option in there someplace that says "Gimme all my games now" that I've just never noticed.
Regardless, if you are missing EP entries in Origin that should be linked to your account, be sure to hit the "i" button or right-click on the TS3 base game box icon to see if they are hiding "inside." If not, only EA/Origin customer support can help with already used errors or missing codes, provided you can prove to them that you have purchased the item at some point. They're usually pretty reasonable about it unlike with tech support where on a scale of 1 to 10 I would give them about a -7 and even that's being generous.