returning of the Bad gas heater

I bought a heater at Builders warehouse,kempton park. I received a very horrible service from the returns desk , as well as from the store manager. I had to return the heater to the store , as it game me problems when switch it on , I would have to do the process for way too long, before it get switched on , whereas sometimes I would do that process and the heater would still not get switched on and the problems continued until I decided to , just return the heater because I couldn't deal with the problems anymore.

when I got to the i told the lady who was working at the returns desk , that I brought the heater back and would like to get refunded(Voucher or cash) , As for the gas heater ,I cannot deal with using it ever again. The lady then refused to refund me and told me that according to their procedure the heater have , to be taken in for repairs , and then after 14 days I contacted to come to the store , I told the lady that phoned me that i am going to get refunded , then she said i will have to speak to the manager , after several days i went to store , where i was told to wait , the lady at returns desk got me waiting for over 30 minutes , for the manager ,while she was busy assisting other customers that came after me , she was rude and shouted at me everytime when i asked about the when the store manager , was going to come and attend to my query. then when the store manager arrived ,she refused to refund me. what does Builders expect me to do with a heater that does not function well , when they claim its new. come to think of it ,the box of the heater looked old and faded , the manual booklet was teared off , the front area that shows the fire when its on , looked burnt a bit. it could be that the heater may have been returned to the store , and the heater may have been taken back to the floor , and then sold to me ,so May have not being the first customer to buy that same heater. Builders warehouse Kempton park does not care about the customers and sells bad products that are not supposed to be on the floor shelves. I must say that I was very inconvinienced and very disappointed by the service offered by both the store manager and returns desk two ladies.