Just to double check the fault with you is it as soon as you set the timer the light inside the oven comes on even though you have the oven switch turned to off?
If so then have you tried to use the oven still to see if it work and the fan comes on and it gets hot when turned to oven setting?
Ok this will be either a fault selector switch or a wiring fault in there.
As the light shouldnt come on when you set the timer. As the light only comes on when you turn the oven selector switch. So as you have the light comming on even when the switch is set to off then its either a fault on the switch itself or the light is wiried wrong which can happen on a brand new appliance as ive seen it before myself.
As its new then just get onto Zanussi or the retailer you got it from and they will call out and fix it for you.
If you need anymore info just get back to me.