FAULTY BRAND NEW DEFY - NO SERVICE

I have reported my brand newfaulty Defy oven on 6 December after trying to use it for the first time and received a job number. A technician was assigned for 9 December. He didn't turn up. I called on Monday and my case was expedited. Nothing happened. After that I couldn't get hold of anybody. I actually don't want my Defy stove/oven anymore as I have lost confidence!