Can you give a link/proof that the one who sends you a message is indeed the CEO or the ANN poster? I can't find one on their thread. While the name is identical, someone can make a fake profile too.
EDIT: I've joined the group and find the admin with an identical username. Here's the UID details:
@Ceahy2k
Id: 222297844
First: Viewhede
Last: Haastrup (ceah)
Try to use userinfobot and check if the details are similar to the one who contacts you.