A couple things come to mind.
1. If the contacts were from Facebook exclusively, then removing FB would remove those contacts.
2. More likely, they were "joined" contacts set to only display the Facebook entry (avoids duplicate listings in the Contacts app). Go into Contacts and press the
Menu key, and then
Contacts to display. Initially, try selecting "All contacts" and see if that restores some or all of your contacts. If not, exit the app and goto
Settings >
Accounts and select the account(s) that you think may have held your contact friends (start with Google). Ensure that "Sync Contacts" is selected, and then do a "sync now." Repeat for any other relevent accounts, and then reboot. You may have to play around with the
Contacts to display that I mentioned earlier, to get things to display the way you want. It sounds like a lot of work, but you only have to do it once.
BTW,
acor IS the Contacts app, so there could possibly be a problem there as well. Try the above first, and if no-go, go into
Settings >
Manage apps, scroll down to Contacts, and then Clear cache & data. Note that clearing data will remove all configuration settings in the app, so be sure you record them somewhere before doing that step. GL!