Second Hand Broken TV for R10 000?????

On the 28th April 2018, my sister purchased a TV and paid R10 000 cash as a gift. A few days later after the gift was opened, it was discovered that the screen had a defect. This was reported to A & E Hyperworld. They took the TV in and it was allegedly taken to Samsung. As per Samsung's report, the TV had been on for a few hours and therefore A & E Hyperworld is refusing to fix or replace. Really, how else would they have known it had a defect if it wasn't turned on and why would they not turn it on because it's a TV not an ornament? They don't want to take responsibility, what are we to do with their broken second hand TV?