Faulty or off food products

I went and bought myself a heater at shoprite eikestad mall. But after I have in only for a month and half it not working anymore. Or actually it is a 2 bar heater only the one bar is working. So it seems they sold faulty products to the customers. And there service at the tills as well as in store if you ask something it seems like they do you a big favor to help you. Terrible service. I pay in full for the heater not half price. Now I only have like half of heater which is unexceptable. I did previously bought other things also there like food which was off, but unfortunately I first notice it when I was at home. And for me to go there because it is very far from where I stay is a big problem, and I didn't always have transport available to go there. Now I actually lose my money in the process and I did contact there customer centre but they also didn't respond at all. So must I just lose my money or what? I hope after my review to hellopeter they will respond on this.