In terms of contract and goods not fitting description, which can still apply to broadband services, but it is difficult to make them stick, since for example TalkTalk can only talk about speeds for services running on their network.
e.g. if downloads are slow over HTTP from a server in Japan there is nothing for them to answer for, if sites in the UK or on talktalk network are fast.
Also is the traffic P2P in its nature, as they no traffic shape that at peak times. They don't slow down other stuff, beyond the fact that it is a contended service, and if 2 million people are trying to watch Doctor Who on iPlayer at the same time, then things will slow down.
It is this contended slow down I believe you are referring to, whereas agent was probably talking about the management KPI pages.