********** Customer service

I have been trying for two weeks to get my oven repaired by defy. I logged my first call on the 16th, they only booked it into their system on the 17th and on the 18th a technician finally came out. All information as to what was the problem had been communicated with the details of the unit however the technician didn't have all the right spares and left. No word for the next two days, so after multiple calls, the technician arrives back on Saturday the 21st. Replaces a thermostat and element and says all is in order. Monday, 23rd, I try to use my oven, it trips and switches off, the very same issue I called about to begin with. I have called the call centre back several times trying to get this resolved as of today the 30 November, I still don't have a working oven nor has anyone from Defy called me back. This is ********** service. Why use authorised agents? I would be better off getting anyone that repairs appliances to fix my oven.