Please try these steps:
For devices running iOS4.x, iOS5.x or iOS6.x:
1. Double tap on the home-button so that a row of icons (open apps) appear at the bottom
2. Tap and hold any of the icons until...
Retype your password in case you were connected 8. Launch Hay Day, tap on
the Settings icon (upper left corner) and tap on "Facebook - Connect" 9.