You're forgetting about the AUP, especially this part:
Customer Communication
Please remember that the staff at this* are, like you, only human. We expect to be treated with the same level of respect as you'd expect us to treat you, so please bear this in mind when communicating with us, and more importantly before clicking the "Send" button.
We reserve the right to ignore and discontinue any correspondance we consider personally threatening, abusive or otherwise intended to invoke negative responses to the person receiving them. Legitimate and constructive criticism, however, is strongly welcomed - providing you can deliver this to us in an appropriate and sensible manner.
Abusing members of staff is absolutely not tolerated, and will result in an instant account termination.