Bad Service from OK Furnitures Botshabelo Sopping Complex

I bought Gas Heater at OK Furniture Botshabelo Re Hola Shopping Complex in May 2021, it only worked for a month. I returned it to the store and they accepted it for repairs. Today (03/08/2021) I went to collect it and they gave me another one, only to find out that it still gives me the same problems as the previous one. I don't understand their level of service. I'm now waiting for manager to contact me for what I don't know. What I want is my refund that's ALL. Their service is bad, I don't wish anybody to experience this incompetence.