Bad service from OK furniture

Hi. I've got a big problem with the service I've got from OK in Randfontein. I bought a Defy stove from them and had problems with it from the start. Plate 1 works from 1 - 6 with 1 highest an 6 low. I reported it an 3 technic teams came out with no success. My house almost burned down as the kids knows that one is low and they went to play. One of my wife's expensive pots melted and we had to through it away. The latest from the store is "Mr Kock you have to stay out of work as Defy will sent a chief technician to your house so that you can talk to the Boss of Defy while he is at your home"! Come on this is not customer service. What about my inconvenience caused by this. I've got a contract with OK and not Defy. Please help. ********** 048