SMEG gas oven malfunctioning, and SMEG technicians not able to get it right.s with this oven,

We bought a 5-plate gas oven which was on special, expecting it to be better than the our previous brand. But it is very hard to control the temperature. The oven kept going off within 10 minutes, so SMEG sent technicians to fix the problem. They blamed the thermocoupler, and replaced it under warranty. But within a short time, the same happened again. Lockdown started. After the restrictions were lifted, I had it repaired again. I had to pay, because the oven was not under the 3-year warranty anymore, even though it was one and the same problem (which they did not fix the first time round). After the second "fix" the same thing happened. I then had to pay for imported parts. When they eventually arrive in SA the technician replaced these parts. But ever since that day, the oven seems to have no thermostat. It gets so hot (at even the lowest setting) that we cannot touch the controls. I am afraid they will once again make me pay for what now seems like a missing thermostat. The oven and especially the service was a huge disappointment. This overheating tarnished the stainless steel outer parts, which is unsightly. One can only hope that they will also replace the parts that were overheating after the technician last came here about 2 weeks ago. What was supposed to be something very special ***ning a SMEG oven), has become one of the worst buys I have made. We now rely on a cheap Defy oven that does a much better job than the SMEG oven.