Zanussi Intelli:set faulty defrost timer on computer?

I have a Zanussi Intelli:set which is just under 2 years old. I'm in New Zealand and cannot get parts for it here as it is imported (made in spain). The fault is it is not defrosting the freezer, which ices up and no cold air flows into the fridge. Everything else has been tested (heater etc) and is fine. So can only be the computer. Can you supply me the part and what details do you require from the fridge. Thanks