Transit visa to Hong Kong

Hi there,

I hold an Iranian passport and I live in New Zealand, I am in Spain on holiday and I will spend one month here. My flight back to NZ goes through Hong Kong, and I will spend one day there.

How do I apply for a transit visa to Hong Kong in Madrid?
Where to go?
What are the documents I need to provide?

I called this number 917414728 many times and they played a recorded messages which said I need to call them from 3 until 5 on Monday, which I did, and the answer was the same recorded message. I also went to the web site but it was down and not operating.

Thank you