The Disputes Tribunal says people are being denied justice because of an unfair and outdated limit on the maximum amount they can claim.
Principal Dispute Referee Peter Spiller says the limit barely keeps up with inflation and is leaving some claimants thousands of dollars out of pocket.
For the past decade, the most money people have been able to claim from the Disputes Tribunal has been $7500.
By comparison, the limit for the Motor Vehicle Dealers Disputes Tribunal was raised to $50,000 in 2003 and a bill is before Parliament that will allow the Tenancy Tribunal to match that.
Mr Spiller says the tribunal's jurisdiction is now "desperately" out of step, and people are having to compromise their claims, some by thousands of dollars.
Consumer New Zealand says the Disputes Tribunal's current limit on claims means it is not fufilling its role of being a speedy, fair and low-cost system to deal with minor disputes.