Customers who ordered from Forever 21’s plus-size collection got way more than they bargained for this week.

The retailer sent Atkins low-carb lemon diet bars to its customers, which included those who purchased plus-size clothing. The tone-deaf move was called out on social media as a prime example of fat-shaming.

After the news broke, the fast-fashion brand told Jezebel that “from time to time, Forever 21 surprises our customers with free test products from third parties in their e-commerce orders” and that the Atkins bar was sent to customers who ordered any item, not just to those who ordered clothing in larger sizes.

The retailer added that the Atkins bars have since been removed from outgoing packages. “This was an oversight on our part and we sincerely apologize for any offense this may have caused to our customers, as this was not our intention in any way,” Forever 21 said.

Regardless, shoppers didn’t appreciate the “surprise,” sharing photos of the insensitive freebie on social media. Twitter user @CaileeArgudo commented: “bought a swimsuit online from forever 21 and they sent me an atkins bar along with it lmaoo thank u for reminding me that i don’t have a beach ready bod.”

One Instagram user, @MermaidQueenJude, dedicated a whole post to the faux pas, writing, “It is so dangerous to body shame and suggest that someone eat less or go on a diet, you don’t know their history with food. As someone recovering from an ED [eating disorder], this would’ve set me back so far.”

She went on to berate Forever 21 for the partnership with Atkins: “How dare you endanger your customers like that?”

In an statement emailed to The Post, Forever 21 added: “Today’s Atkins is focused on a lifestyle nutritional approach where everyone can benefit from overall health and wellbeing. Our brand evolution is reflected in the current marketing efforts to highlight the health benefits of eating a low carb/low sugar Atkins lifestyle, with a portfolio of nutritious and delicious snacks for everyone. The intention of sampling Atkins products is to share snacks that taste great with optimal nutritional benefit.”