My new 65" Sony has never been connected to the internet. We can't get 4K resolution, presumably because it's never been updated. Sony tells me they don't have

My new 65" Sony has never been connected to the internet. We can't get 4K resolution, presumably because it's never been updated. Sony tells me they don't have a USB update available "yet." Had I known this would happen I wouldn't have bought it - my old plasma is still working. I didn't wish to connect just for the update and then disconnect over concerns that they would use that connection to download ads onto the firmware at the same time.