Complain about my stove

hi, i bought a Defy stove from Game mall of the south, it only worked for 3 weeks ,then i went back to game ,Defy send a technician ,then after 2 weeks it had the same problem, this time the electrician from Defy come and opened the stove said there is a cocroach,it has spoil the stove, they cannot do anything , game said no refund or exchange. please hepl me