Log out, then link your EA/Origin account to your gamesas account.

1.Log out
2. Click 'Sign In'
3. Click on the right side red button, under the EA/Origin header.

This fixed the 403 errors for me, and should hopefully work out for you as well.

Cheers.

I'll try this because the forums are driving me crazy with errors and overall failure.

EDIT: well it gave me an 'error' first time then i tried it again and it said already linked so either

A) I already had it linked and thus will change nothing or

B) it 'linked' the first time i tried and just gave me a 'derp' response.

either way it seems to be much better at the moment of this writing (the forum is actually responsive!).