Feeling sorry after hearing about your loss. You didn't feel it necessary to take the help of trusted escrow service before making the payment. You made the first mistake by choosing a service which is completely new and service provider used some new accounts to bump his ANN topic. I am seeing from my end that all the guys who have replied there have a interesting similarities and that is all 4 accounts registered on 2017. Isn't that looks weird ?

By the way, Thanks for creating the topic to make us aware about another scammer. I will add this scammers details on ★ List of Proven Scammers (Bitcointalk users Only) ★ soon.

Note: "OP" Please update your topic with the flag link which have already opened by you. 

Can you share another screenshot where he gave you the ID of the chat app and also which chat app is that? Just need to verify the chat screenshots as you presented. Will tag the account after it is posted here.

Also if you don't mind me asking what lessons you learned from this incident?