Rude and unhelpfulness from a big retailer

Bought a Smart TV from Makro Edenvale. I plugged it in and set it up and all was good and working. through the box away. Worked for 2 days then on the 3rd day, nothing. Took it back to Makro with the receipt and they needed the box for a refund. They are adamant they told my mother to keep the box for 14 days. It was bought on black friday weekend, things must have been hectic. My mother says they did not. I even suggested they give me a new TV and keep the box, they said no. They have to send it in for repairs. I've dealt with retail and their returns. Not all their returns come back in the packaging. Now they want to say otherwise. Oh and on top of it, the manager of the TV division was rude. He would not let me finish talking, kept interrupting me. I had to tell him twice to keep quiet and let me finish talking before he talks. That just irritated me even more. This was not the first time i have had shocking service from Makro.