"Despite our attempts to explain this matter to them, they've continued to provide incorrect information to New Zealanders through the media," Clement said.
"This continued attack on our reputation is nowhere near the fair play they've been talking about."
Lewis Road is taking Fonterra to court for allegedly copying its packaging and being anti-competitive in the chiller space.
Lewis Road believes Fonterra has copied its milk packaging for its Kapiti Milk range, including shape and labelling which uses a similar cow.
"The thing that drives it home for me is that Fonterra invested very heavily in their light-proof bottle and held it up in being the biggest innovation even but have chosen not to use their own bottle and have copied one that looks like ours. So I have no doubt that it's to confuse because we are getting feedback all the time from people who are confused and annoyed..."
In the advert Cullinane accused Fonterra of negotiating a "greedy" deal with supermarkets which would limit the ability of smaller dairy brands to get space in the chiller.
He said he understood that "Fonterra is looking to use its market power to introduce an exclusionary deal with supermarkets in the North Island that would all but remove non-Fonterra brands".
The deal would give Fonterra's white milk brands 95 per cent of the chiller space, he said.
A representative for the Countdown supermarket chain this week said it was not involved in any deal with Fonterra.
"Countdown does not have any deal with Fonterra of this nature, and would not enter into any agreement like this," said Countdown general manager merchandise, Chris Fisher.
"We treat all of our suppliers fairly and shelf space is determined based on the merit and popularity of each product," Fisher said.
A spokesperson for Foodstuffs North Island said the company had "an agreement in place with Fonterra, as we do with other suppliers including Lewis Road Creamery, to supply a range of dairy products, the terms of our supplier agreements are confidential".
"The issue here seems to be a competitive one between Lewis Road Creamery and Fonterra in the premium milk market," the spokesperson said in a statement.
Cullinane hoped to settle with Fonterra before the lengthy court process played out.
"I'm just hopeful that Fonterra's game is not just to play it out until we've run out of resistance."
Cullinane is a former advertising industry executive and is a director of NZME, which owns the Herald.
