I'm sorry that this has given you so much trouble, and thanks for letting me know what you've tried thus far. It'll really speed things up.
Could you add some more details on your connection: are you using a wired or wireless connection? If possible, what's the model number for the wireless access point/switch/router that you've connected to?
Also, what is your description of the error that Netflix gives you?
I have a new SMART TV, model UN55ES6150FXZA. It will not connect to NetFlix. It connects to all other apps. I have read other discussions & talked to Samsung and Netflix for hours. I have: assured TV firmware is latest; reset SmartHub; reinstalled SmartHub; changed DNS to manual 22.214.171.124; changed DNS to 126.96.36.199; changed DNS to 188.8.131.52; set clock to manual; set clock to auto. Nothing works. HELP!