Facebook Does Not Update
Edit: this seems to be an issue that Facebook recognize. It's an issue with the Facebook application, and also not a generalised Play Shop issue.
This is what worked for me at the very least.
- Settings > Apps > All > Google Play Shop, Clear information and Clear cache
- Settings > Applications > All > Google Play Provider > Manage area, Clear all information and also Clear cache
It doesn't injured if you restart your phone before you try updating facebook again. As well as, the install was SLOW. Just at least 4-5 minutes. But, it did job. If not try to uninstall it, or simply wait for a fix.