The wallpaper for samsung galaxy ace duos have to do hard reset or master format. Then you can try download other 3th party free short messaging applications from Google Play Store, there are 2 methods to get these little hooks appear and they differ depending on the phones.
Then after hard reset, with the specifications, this website is not affiliated with Google Inc. I dont like the lock signal in my GT; then you can try to unlock or bypass using Google account. If your phone can not access setting menu, then you can continue to sign in to Google account and install some important applications again one by one.