The Commerce Commission has released a 2016 Consumer Issues Report, showing that consumers complain to it most about price (26%), goods (23%) and services (22%).

The report uses information from a wide range of sources to take a detailed look at the complaints received by the Commission as well as looking at the wider consumer environment and the influences the economy and technology have on consumers.

Commission chairman Mark Berry says the report shows that one quarter of its Fair Trading Act complaints relate to just 21 traders. The report notes that many of these were large retailers with a national presence and a high volume of sales.

He says complaints in a number of areas have increased significantly since 2013, with motor vehicle retail complaints increasing by 70%, complaints about contracts doubling, and complaints about debt collection "significantly increasing".

Non-bank lenders feature prominently with complaints about non-disclosure, targeting of vulnerable consumers and irresponsible lending. While finance companies make up just 3% of the credit market, they accounted for 43% of credit-related complaints to the Commission.

The report says 35% of Fair Trading Act complaints were about seven industries: telecommunications providers and carriers (9%), domestic appliance/electronics/phones (9%), motor vehicle retain (6%), airlines (3%), online-only retail (3%), electricity retail (3%), and supermarkets (2%).

It notes that FTA complaints about telecommunications providers have increased by 20% from 2014 and have doubled from 2013 levels.

Spark was the most complained about trader in 2015, followed by Vodafone. Complaints about charges generated a third of related complaints against both providers.

The 21 traders that generated 25% of Fair Trading Act complaints in 2015