Went back to JBHIFI, they were great and agreed that the TV should not be like this, and booked a service rep from Samsung to come and take a look.
The technician arrived with a new TV panel. He asked what was happening with the TV, I told him that the light was leaking and that it is especially bad at night. He immediately knew what the problem was (before even looking at the unit) and told me that replacing the panel will not fix the problem, but would probably make it worse. I told him not to as it would be wasting my time. He filled out a report stating "No obvious fault found". He also wrote on the report that I disagreed with this. He told me to argue my case with Samsung and he was on his way. Strangely enough on the report, there were explicit instruction "DO not take photos of netflix login page" which is bizarre because it is the easiest and clearest way to show that the problem is occurring. It kind of feels like they know its an issue.
Anyway, a few days past, I get a text to give Samsung a call. They tell me that because the technician wrote on the report "No obvious fault found", they refuse to provide a remedy. They encouraged me to get JBHIFI to provide a remedy. I asked them to look at the photos and they acknowledge that there is light leaking, but say "they can only go off the report". I also tell them that the technician told me to argue my case, and he said "he should've said that.
Any advice of where to go from here?