Can't login on the TS3 Launcher to download Store Items

Okay...

So this has been very annoying now; I bought all of the packs in the EA app and I can't use some of them. I have already redeemed the codes that were sent in my email, but I still cannot use the worlds I bought. (i.e. Roaring Heights and Dragon Valley)

I have tried changing my password, clearing the cache in Internet Explorer and or Chrome, and I even tried reinstalling the game.

Everytime I try to download the files in-game via the "..." > Open Downloads Dashboard, the game would minimize and open the Launcher, then it would ask me my username and password, but each time I input my details, the login screen just pops up again...

Can anybody help me here?