Makro is irresponsible! Where's my heater?

I'm writing this as a grandmother with a heavy heart. I purchased a Russell Hobbs heater at the beginning of July to use during the winter since my house is freezing, and I take care of my 11 month old grandson during the day. The heater worked for one week and suddenly stopped working. I asked my son to return it to Makro and till this day we haven't received any feedback from them. All we got was a reference number (251395) and that's it. Whenever I call I'm told that they'll get back to me but nothing. My 11 month old grandson is constantly sick with the flu because Makro isn't responsible enough to get back to an old lady, who paid for a heater in cash. It's not August and I'm still without a heater.