Many users experiencing problems to connect to their facebook chat (the intergrated one).
This is because of Facebook chat api, however you need to complete a little step before we begin on how to connect.
First go under settings and disable the battery power saving, then make sure you have Facebook chat enabled under Messaging options.
Then what you're gonna do is go to Windowsphone.com and login with your Microsoft account (the one you gave on phone's first startup), type your phone number and everything required.
Then from the pull down menu select Find my Phone, try to locate it or even ring it.
(Click to enlarge the image if needed)
Once this task is completed you can connect to your intergrated facebook chat.
Written by Constantine, hellaskafeneio author team.