Builders Newmarket is full of nonsense

GAS Heater faults I placed an order on the 27 of June 2020 for a gas heater and gas cylinder which never got delivered simply because they didn't have stock. Went to the store, Newmarket Alberton, they gave me a heater and a gas cylinder which was nonstick and refunded me the difference which I was happy with. When I got home, heater was not working, the next day they gave me a new heater which worked when they tested but when I got home, didn't work, went back gave me a new one also and changed my gas cylinder as that too was faulty. once again, now my heater not working, went back for a refund or new heater but they don't have any and they can't refund me as I don't have a box which I lost in the process and now I have to wait for next stock which they don't know when to get another new heater and how will that heater differ from the ones I have been given? this is all goldair heaters. Someone needs to assist me ASAP, its cold and with this load shading, my family will get sick. FIrst order#**********. I will appreciate the help ASAP