Product promoted as eco-friendly but seems to be nothing of the sort

Environmental claims are subject to the Fair Trading Act 1986. Businesses must not mislead consumers, and the Act also prohibits making representations in trade without reasonable grounds for them, which is often described as the substantiation requirement. If a business cannot back up a claim such as carbon neutral, that alone can breach the law even if the claim is not proven false. The Commerce Commission has published guidance on environmental claims and expects them to be specific, accurate and supported by evidence. You can ask the company in writing to provide the basis for its claims and then lodge a complaint with the Commission if the answer is vague. A refund on the ground that the product was not as described may also be worth requesting.