Hisense bad customer service

Hi, I have bought a Hisense65'' UHD Smarts TV with HDR and Digital Tuner on 7 July 2010, but get the whole time this error (Netflix error ui-800-)when switching to Netflix. It doesn't even give me an option to sign in on Netflix.

I was in contact with Veronica Ramutsindela and to open a job number ***. Model=65B7100UW Serial=3TE65F***1EFJSJ0097

The technicians visited me twice this week on 21st July and 22nd July without fixing my TV. They have advise that the unit need to be replaced, and that they will be in contact with support.

I have since send numerous mails to Veronica Ramutsindela at ***, but nobody comes back to me.

I just need to understand when the TV will be replaced, and why is it so difficult to inform your customer on regular feedback.