Answer: The consumers who thought the advertising for yogurt was misleading will complain to the Federal Trade Commission (FTC).
The Federal Trade Commission (FTC) was established in 1914 by the Federal Trade Commission Act. It is an independent agency whose aim is to protect consumer interests and eliminating and preventing anti-competitive business practices.
In USA, not all complaints of false advertising can be reported to the FTC. Since the product in question is a dietary supplement, it can be reported to the FTC.