Defy oven

After paying a fortune for a "top of the range" eye level oven, I have had the 4 different technicians with four different "solutions" for the tripping of the lights. Since the third technician came a week ago the fan has still not turned off. I was promised that my oven would be replaced with a new one today when there wasn't even one available for collection when the technician wanted to collect it. Wouldn't recommend to Defy to my worst enemy, DO NOT BUY THEIR PRODUCTS.