Defy Slimline Stove Malfunction

Good day

I bought a defy slimline ceramic stove on the 20th July 2018 and guess what, ever since I've been reporting it that it's malfunctioning and their technician seems to break it even worse... I logged a complaint 3 weeks ago that my oven is not working and even today no one has came back to me.. Defy has lost me as a customer.