You could try checking yuor Origin order history to make sure you didn't order it accidentally. Open Origin and select the Origin menu, then Order History, and check All for the time period and scroll through. Did you buy a bundle recently that included it, perhaps?
Another possiblity is that some well meaning forum friend gifted it to you. I don't think those show up in Order History. You might have to go through Origin Help to figure out how it ended up in your game, and maybe they can figure out how to remove it -- maybe deactivate the activation code or something..
I've reinstalled a few times and haven't had issues with not being able to install all packs so maybe they've solved that issue in one of the Origin patches.