I found this article that looks interesting, as recently I've started being frustrated by not being able to sign up for services because of this attitude to have service agreements that are practically in my opinion useless, I mean if you let me sign for something that can be changed at any time, why even bother writing it/accepting it
I'm shocked anyone has ever accepted any of that as reasonable. At a minimum a contract should specify a protocol for reconvening and renegotiating terms. Anyone coming to me with a "these terms can be changed at any time" is told to get packing and come back when they want to do business.