Hi all!
For anyone who's tryin to log into your tapped out account and it redirects you to sign up can try this methood that worked for me.I had the same problem all night tonight, but there is a way into your account if you have, at some point, accessed your Facebook account to invite contacts to be your friends in the game.
1. usig your mobile device, go onto the origin/EA website: www[dot]origin[dot]com/us/login .
2. Make sure you are logged into Facebook on the same mobile device as before when you initially created the account on your phone.
3. Select the "Or, sign in using your account with: Facebook" option.
That should automatically sign you into your account and your email associated with the account will be displayed. Unfortunately when you sign up via a mobile app, it doesn't have you verify your email address. I imputed my email account wrong and web I wet to log back in my real email address wasn't working. In order to change my email I will have to contact customer support directly due to their security policy. What I choose to do was created a whole new gmail account with the spelling error I made when I initially signed up and had an account verification email sent from Origin again. It's tedious but it works.
Hope this helps. All the best!
(To anyone reading, sorry for any typos. It's very late/early and in too lazy to spell check ;P)