You are only allowed to do or be granted (if you don't use it) one single Work and Holiday visa, if you are eligible for it. And one such visa allows you to stay in New Zealand for up to a year, depending on your citizenship/residence. According to the tourism board of New Zealand, one condition to get a Work and Holiday visa is that you:
Have not previously visited New Zealand using the Working Holiday Scheme visa (or been approved for one).
Note also that your main reason should be to travel and visit the country, not work, i.e. work should be a way to help you fund your travels, this is not intended for workers to immigrate.
If you are interested in immigrating to New Zealand and getting a work permit, this website is not the right place, but you can ask your question on our sister website expatriates.SE. Also note that it depends on your citizenship, so I would recommend you to give yours when you ask your question.