I do not know whether you are scammed or not but I always feel people have good intentions to scam when they post their ad here but in return they want to be contacted in telegram,facebook and twitter.

Just make sure that you leave responses in the thread too, so that everybody know that how many people are dealing with user and how the deal is going on.

PS: I am not blaming anybody but it is my personal observation in this forum that somebody is interested in making deal outside the boundary of this forum is a red flag.