You may have seen the ads for Skechers’ Shape-ups shoes featuring spokesmodels like Kim Kardashian and Brooke Burke.

But the FTC says the claims made within those ads and others like them were false, and it’s now ordered the shoe manufacturer to cough up a $40 million fine.

Skechers said the $100 sneakers’ design promoted weight loss and toned muscles, but the FTC said such assertions were deceptive and misleading to consumers. The action brought by the agency also included Skechers’ Resistance Runner, Toners, and Tone-ups shoes.

People who bought the shoes will be eligible for refunds, though how much they’ll get back is unclear. The FTC did say that most of the $40 million settlement will be returned to consumers.

It’s not the first time the FTC has cracked down on the makers of athletic shoes. Last year Reebok faced similar trouble over its EasyTone walking shoes and RunTone running shoes, and eventually paid out $25 million in customer refunds.

“The FTC’s message, for Skechers and other national advertisers, is to shape up your substantiation or tone down your claims,” said David Vladeck, director of the agency’s consumer protection bureau, adding that for millions of buyers, “the only thing that got a workout was their wallet.”