Many of our members try really hard to be flexible with payment options (e.g. set fees, contingency fees/No Win No Fee etc).  If you genuinely can't afford to pay for advice or representation, you might be able to get some help from your local community law centre or CAB.  Further information can be found here:
http://communitylaw.org.nz/
http://www.cab.org.nz/Pages/home.aspx
Be aware that some limitations (e.g. income testing, time limits on advice, inability to represent you formally) may apply.