@SdwllFam Please remove the screenshot from your post, since it shows your email address; that's not something that should be on a public forum.
It sounds like you received only a code for the one stuff pack, not the base game. While there have been plenty of bundles that include the base game and a pack, I've never seen one that includes the base game and only a stuff pack. So I think GameSync is either incorrect or misleading you here.
Regardless, if you had only one code and it only listed the stuff pack, there's nothing you can do to add the base game to your account. EA does not offer support for purchases from third-party sellers. If the product keys work, fine; if they don't, you need to take it up with the seller. Sorry I don't have anything else to offer here.
