24 hours later and my account has been restored and my Diablo 3 characters rolled back to before the compromise. Unfortunately my entire Battle.net balance was used to purchase World of Warcraft game time, which has not been returned to me. I reopened the support ticket and asked them to look into this, so we'll see what happens.
Along with a half-dozen automatically generated Blizzard emails telling me my account has been locked, a name change forced, etc, I got this canned response:
This is the latest response from Customer Support:
My name is Leynril and I hope this message finds you well. I'm sorry that we couldn't have a conversation while you were online (it's not possible with D3), but I just wanted to let you know that I got your ticket about your reported compromise, and I have taken an in-depth look into this for you. Given that we're basically communicating through email now, this message will likely be a bit long, so I appreciate your patience. I wanted to make sure to cover all the bases. =)
As I understand it, your reason for contacting us is to have the account investigated. If this is correct, then the rest of this message should make sense and give you a clear and accurate resolution. If for some reason I've misunderstood your request, please feel free to reopen this issue at your earliest convenience and we will clarify it a bit more. =)
While investigating this for you, I discovered your D3 account has been compromised. The account currently has a security lock placed on it and I have emailed you details regarding restoration of that account and how to recover it to your email address. I would greatly appreciate it if you could review those emails as soon as possible.
Before I go, I want to reiterate just how much we appreciate your patience, and just you as a whole. <3 Our game wouldn't be what it is without valued and dedicated players such as you. If there is ever anything we can do to make your experience more enjoyable, please just let us know! It's our goal to provide you, and all players, with the most epic customer support ever! =D
Thank you for letting me borrow some of your time today. I certainly hope that I have helped you with your situation.
Game Master Leynril