Paying for a broken thing

We bought a new Defy fridge freezer combo in December 2017, the fridge gave problems and we logged a call the technician came out on 3/3/2018 and changed the thermostat, 2 days later the fridge again started giving problems and everything in the fridge went off. We spoke to teljoy and they then again send a technician this time from defy. Who did nothing took photos and left. Fridge still not cooling. When we spoke to teljoy to say how we feel and want a new unit or to cancel the deal. Dominic said that Zanele would get back to us at 15:00, we phoned again and was phoned back by Courtney all in the technical department I was told that she would get back to me as she needs to check with her manager I asked it it would be before end off business and was told yes. When I phoned again at 16:45 I was told she left already in the meantime I am paying for a thing that is not working the way it should this is the worst service from teljoy.