once in a while spam? Goup chat call

So im in a group chat with my friends and we don't know what's happing but some reasons we keep getting calls within the group chat and we can't tell who it is because instead of telling which person is calling it just tells us everyones name and im not sure what to do. I had shut down my phone and I even blocked it were unknown numbers can't FaceTime me. but I really wanna know what is happening I tried almost everything. I really don't want to factory rest my phone. please some help because im also scared to tell my parents and something bad happens. I really can't afford a new phone. please ignore the nasty name

[Edited by Moderator]