Poor Customer Service

So I'm currently having issues with my Defy Hob plates which are slow. i logged a call with Game Stores in turn logged a call with Defy . Call was logged somewhere on July. A Defy technician pitches up on the 2nd November 2023 to assess the unit and found that the thermostat and light in the oven needs replacing and according to him the plates were working fine . Note that we use the stove everyday so we should know better. After the 2nd i did not get any feedback from Game of Defy so when i enquired i was told that i refused the service hence it was not repaired. Anyway after much frustration , a technician came out on the 2nd December 2023 and tested the appliance to find that the thermostat and light is working fine . So my question to DEFY is which is the correct assessment and obviously i am doubting their service due to the conflicting results. DEFY is still to prove which is correct and WHY there would be 2 conflicting results. So they finally stated that the plates are working fine, to which i am stating that it is not. With all due respects how can i take DEFY assessment as correct when there are conflicting results . To date the appliance is not operating and im really inconvenienced.