No HDR

I bought a 4k 65' Hisense TV. When I tried to run HDR I was advised that I need to run an update. The update was downloaded but it would not run. I eventually contacted Hisense on 28 December 2018 and was elated to receive a response almost immediately. I was asked to furnish proof of purchase and fill in a form which I did. I was then told that a technician would be dispatched to attend to the problem.

This is not been done. Even though I have contacted Hisense via e-mail and called. It is now been over a month and my situation is simply being ignored.