My father got hacked in a very strange way, he had the 2 factor authentication on his account, but somehow someone was able to connect a fake instagram account (nghiem.phuc.85944) to his Facebook (https://www.facebook.com/562789865/). HOW?!?

This fake account has now been deactivated but since my father’s Facebook account was linked to it, it was deactivated too.

I have no way to report that from the account since FB ask me to appeal from the Instagram Fake Account, of which obviously I have no access!

There is no support, no way of reporting, I really don’t know what to do. He has many work connection on his account and now everything is simply gone?