We've resumed all services for OP. The tl;dr is this was a new account with no billing history and on track for a relatively high monthly spend. We attempted to authorize the card on file for the projected amount, and the authorization failed, leading to automatic suspension.

This is obviously overzealous abuse management, and we will fix our systems so this kind of thing never happens to legitimate users.

To OP and others who may have been affected, I'm deeply sorry.