Builders refusing to exchange a burning Gas heater or a refund! They tested it and saw the fire and yet still? HELP ASAP

I experienced pathetic service yesterday at Builders Warehouse in Sunninghill. Last year July I bought a gas heater from Builders Warehouse Sunninghill, I used the heater and it started showing sparks, misfires, literally burning the panels above the heat area towards end of winter last year. I stopped using it and forgot to take it in and only now I did because obviously it is winter and I remembered.

I got to Builders with my receipt and they took it to test it and they experience the very same I did, I WAITED FOR OVER 30 minutes to get the help. The manager advised I took the receipt and heater to exchange/refund. I got to refund department and I also waited for another 30/40 minutes with only one person working, I was not the only frustrated customer. Then a cherry on top they tell me they will need to book it in with the supplier and the turnaround time is between 14 - 28 days, meaning I will only get it towards end of June. WHAT IS THE POINT FOR GETTING A HEATER TOWARDS END OF WINTER? WHAT AM I SUPPOSED TO USE TILL THEN? I have kids at home that need heat in the house.

I am extremely frustrated and upset. I even asked for the supplier number - New World apparently, but they are not of assistance neither of which I shouldn't need to even speak to the supplier directly because I bought the heater at Builders and not New World.

I want a new heater - I WILL NOT RISK BURNING MY HOUSE DOWN WITH MY KIDS INSIDE! It was tested by Builders so what more is needed? To burn my house down?

I want a NEW HEATER OR A REFUND, PERIOD!