Urgent Help Required- RE: New Zealand Visa Refusal

Hi folks, looking for some urgent advice regarding NZ working visas.

My brother has been studying there for the past 6 months or so, and had planned to stay for 6 more months by getting a standard Irish working holiday visa.

Here's the problem: he initially applied for a working holiday visa, and was sucessful, but when he decided to study there he contacted immigration and was told he could switch to a student visa and not work (this was before he'd even arrived in NZ). The student visa has now expired and his application for a regular working holiday visa has been refused on the grounds that he has already been granted one (the limit being one application)- meaning the one he applied for initially but never used.

He has been told there's no appeal process- is this possible?? It seems crazy!

Any advice from you folks in the know would be much appreciated.

Thanks!