There are some types of legal action that service providers can get, which both force the service provider from droppig you, and also forbid the service provider from telling you why or what has happened. Eg, this happens in banking with SARs; when they drop a client for suspected money laundering, not only can't they tell that to the client, they can't even tell their own support agents.

I don't know anything about your sites or your activities, but based on the behavior described, something like this has probably happened to you.