BK - you already knew these people for what they are, so, while I understand that the find was disappointing, I am not sure it should have been surprising.
We cannot control how others act, only how we react. Letting them know how badly it hurt you can only benefit them and hurt you further.
I would urge you to try not to dwell on it. Life is too short to waste it on faux friends. The whole episode will make a couple of chapters in the next edition of your memiors