Very sad

I need help I bought a Tv at Game in King william's town on saturday 5th and left it at the store, then on Monday I asked someone with a car to go and collect the Tv. The TV came (7th) and I plugged it connected with DSTV, it lighted and within 2 minutes it switched off and didn't want to light anymore. I called Game immediately and they told me to return it, I returned it following day(8th) they told me I must wait for 21 days because they will call technicians to come and check it. I said I want my money but they refused to give me. How can I buy tv cash and get a fixed tv while it's new. Please help me I want my money from Game😡