The Federation of Communication Services - FCS - is the UK Trade Association for the communications services industry representing businesses delivering products and services to customers by radio, mobile, fixed and IP telephony.
Otelo is the Office of the Telecommunications Ombudsman. They to sort out disagreements between public communications providers and their customers. They provide a free and independent service that has been approved by the regulator (Ofcom). Their job is to investigate complaints fairly by listening to both sides of the story and looking at the facts.
Ofcom - Office of Communications are an independent organisation which regulates the UK’s broadcasting, telecommunications and wireless communications sectors. They also set and enforce rules on fair competition between companies in these industries.