Beko stove

Hi ,I bought a beko stove at Hirsch's fourways and the stove doesn't work,I got a technician for the first with one plate not working,second time it was the motherboard not working, third time the stove does not work sometimes ,it gets switched off and the motherboard sometimes doesn't work properly. I told them I want a new stove and they refuse to give me the technician that came gave a report that the stove is working fine while I told him this thing doesn't work and I request to get a brand new stove . This feels like I bought a second hand stove while I paid for a whole brand new stove.the service is very bad.