Pathetic service from Defy (a whole year later and nothing done!)

I bought a house that was newly renovated, and a new Defy oven installed. We only moved into the house a year after it was renovated, and the oven was thus a year old but never used. When we used it, it didnt work, everything burnt. We called Defy in Sept 2016, and they sent someone. They eventually (after many calls) replaced the thermostat in February 2017. When we tried to use the oven, it burnt everything after 10 mins. We called Defy again, and eventually the technician came out after many calls in February 2016 and said he would order the parts. Then...nothing... for months. We keep calling, and in June 2016, a technician came again and said he would order the parts (again! what happened to the parts he ordered in February???). Its now Septembder, and we call and nothing happens! Its 2 years later and we never got to use a brand new oven!!!! we may as well throw it in the dustbin where Defy products belong! Pathetic service!