If I go to the gym and drop 100kg on myself then it is my fault for not understanding the risks, where it is reasonable to do so.
It is reasonable to expect you as a customer of the internet service to understand the service you are using and the costs involved. It really falls on no one elses shoulders.
I do agree that it tends to be over priced and the pricing structure is often confusing but I still think it's within the grasp of most to understand it.