Cadac gas heater

I bought a heater at game wonderpark it was working at first and when I try to switch it on it doesn't work that's when I get back to the store and to exchange it to my surprise game can't exchange my heater as cadac is not replacing they take there products back to their workshop and I will have to wait for 21 working days. What about the coldness and my kids in this cold. My petrol money for this up and down it is so disappointing of them