The FCC applies the transparency requirements contained in its 2010 and 2015 Open Internet Orders that passed muster with appellate court review.
Ironically, AT&T could have avoided the fine if it strategically blended service contracts with FCC filed tariffs. Historically, tariff filing requirements have been vilified as harmful to competition, innovation and carrier flexibility. The FCC has mandated detariffing of many services including wireline and wireless long distance services on the assumption that carriers will self-regulate in a competitive market.
The tariff would have trumped anything offered orally, or by written agreement. Even today, under certain circumstances, incumbent carriers still like what tariffs offer. For example, Verizon still has a web page that seems to like tariffing. The company states that: “Tariffs have historically served as the basis for creating binding rights and obligations between carriers and their customers for telecom services.” See http://www.verizonenterprise.com/us/publications/service_guide/detariffing_f_a_q/.
But of course who wants a fair balance of rights and obligations between carriers and consumers? With binding arbitration clauses and major limits of the certification of class action law suits, carriers increasingly can behave poorly, dare I say cheat customers, without penalty. Occasionally the FCC and FTC step in, and the offending carrier pays a minor fine.