I presume you checked email + accounts in the settings?
Also what build version is your phone running on? (you can check by going to "about windows phone" in settings, if you want post a screen shot, make sure you crop out your IMEI, MAC Address etc)
As on Windows Phone 8.1 social media syncing has been decoupled from the O/S in favour of the Social Extensibility Framework.
Sharing is caring – How the Social Extensibility framework for Windows Phone 8.1 will make things better | Windows Phone Central.
As MS ran in to an issue where for example Facebook would introduce new features and it would take an O/S level update to implement those features. Similarly if there were backend changes, it would break the integrated version of Facebook.