Defy poor quality product and service

I purchased a new defy fridge about a year ago with a 5 year guarantee for about R8000. About 8 months ago the door hinge collapsed and they replaced the fridge with a new one. This was quite kind of them, or so we thought. Since the new fridge has arrived it has never worked properly. It constantly freezes all the items inside the fridge even on the warmest setting. They first replaced the thermostats and that didnt solve the problem. They then changed both pc boards and told me to wait about a week for it to maybe work (bizarre). Now they have said its the door seals. Been waiting for 3 weeks again. This has been ongoing for 6 months now and we are fed up. I have asked for a refund and they never get back to me.