Supermarket giant Coles has sparked the ire of shoppers with dietary requirements amid claims the formula for the supermarket’s ‘Coles’ branded blocks of dark chocolate has been revised to include milk solids.

Shoppers started to call out the supermarket over the weekend on social media, with thousands of people reacting to the news that the chocolate blocks – a favourite treat of the lactose intolerant and vegan communities – suddenly contains milk products in the ingredients list.

Several complainants told Coles their households purchased multiple blocks of the product each week, both because of the Fairtade certification of the item, which shoppers say has now disappeared from packaging, as well as its status as one of the most affordable vegan chocolate products on the market.

“I’m deeply disappointed in this,” said one Facebook user, asking for a reversal of the change. His post has now garnered more than 4000 likes and reactions from other fans of the item, who say they now cannot purchase it because the ingredients do not match up with their ethical and allergy requirements.

“My heart is absolutely BREAKING!”said another shopper. “I’m not vegan, but I’m quite intolerant to dairy and the discovery of your dark chocolate allowed me to still enjoy one of the finer things in life.”

“What the hell were you thinking?” said another fan.

On Monday, Coles had not put out an official explanation to shoppers about the change and the retailer did not respond to a request for comment about the changes prior to publication.

The Coles online shopping portal advertises the 200 gram variety of the product for $2.50, and the accompanying product image includes a Fairtrade label on the front of the packet.

However, images of the new packets shared on social media over the weekend do not have the Fairtrade marking on the front.

Small changes to cult-favourite products have caused mass outrage over the past couple of years, from the change to the recipe for Shapes biscuits, which has since been reversed, to the alteration of Toblerone sizes and news last week that Tiny Teddy lunch-box snack packs were going to be packed differently due to power price concerns.

Branding expert Michel Hogan says with any change to a niche product or item that appeals to particular shopper requirements, like dietary needs, businesses should expect customers to be upset by sudden shifts in design.

“Then there’s a different level of connection and expectation,” she tells SmartCompany.

This article first appeared on SmartCompany.