What is going wrong?
What you pasted is the UTF-8 serialized version of your payload.
If you try it on console, you get:
var json = {"data":[],"message":"\u0639\u0630\u0631\u0627 \u060c \u0647\u0630\u0627 \u0627\u0644\u0639\u0636\u0648 \u063a\u064a\u0631 \u0645\u0648\u062c\u0648\u062f","status":false};
console.log(json.message);
// عذرا ، هذا العضو غير موجود
Google translates it to: "Sorry, this user does not exist", which seems correct (sorry I don't know Arabic).
You need to parse the textual JSON representation from your response. By default JSON will be encoded in UTF-8.