Facebook calls coming through Do Not Disturb Mode

[Polpol1]

Last night I was woken up at 3am when my iphone 4s started vibrating as someone was calling me with a Facebook call (who uses those anyway?).
Do Not Disturb Mode was ON so the phone should have stayed quiet.
Is this a known bug? Can I do something about it? Thanks!

 

[Applejuiced]

Yes, since that's not really a phone call.
Its like a chat client with voice so it will go through.
You can go to settings/notification,messenger and disable notification from it so it will not alert you at all.