Unresolved technical fridge defect

My mother bought a defy fridge last year August, then in Jan this year the fridge started giving problems, then a technician was sent only for the problem to still continue, 3 technicians have been sent and still the fridge doesn't work even now, we are inconvenienced as we had to throw away food that went off whilst waiting on defy to come. We are fed up now. We cant wait any longer as that is impacting us and we are wasting money as we cant use thw fridge.