We are so sorry your mom did this. If you can tell someone where they are, so heidiv or your friend can get them, at least you know they will be safe. And as they are well-socialized kitties, hopefully they'll be okay adjusting to a new home.

I'm sorry, I know we cannot change who your Mom is. All you can do for now, besides what I said above, is to vow never to subject any future child under your care to this kind of heartlessness. Big hugs to you, okay?