So… All of them. Gotcha.

As a curious individual, did you mean TV Closed Captioning or DVD Subtitles?

As a side note, the FCC does have a complaint page for reporting Captioning for certain services and for other issues.

https://consumercomplaints.fcc.gov/hc/en-us/requests/new?ticket_form_id=36040

Info on the Communications and Video Accessibility Act (CVAA)

https://www.fcc.gov/cvaa