I had another post about this, but since this one seems to have the most replies, I will post my replies here.
Our guild name was/is Dragon Army and we are on server 5. I'm the Leader of the guild and very active (so no chance of a champion somehow taking over due to lack participation and disbanding). Went to sleep, all was fine. Woke up the next day and our guild was gone. No messages or anything. I reached out separately to those members that I could find and we've been slowly rebuilding. Based on various discussions when each member was last on, we determined that the guild vanished (I don't want to say it was disbanded, since that implies a voluntary act on our part) sometime between 5:10am-8am EST (after the daily reset). We had 41 members.
I don't want to focus on contest rewards--those were not affected. But here's what we did lose--war rewards and tokens for the week; all our temple streaks; crypt and the various gold associated with it (no one can attack crypt for 24 hours after joining a "new" guild), plus having to start over once again on easy level and work our way up; crypt tokens (earned from a large, active crypt and all the various temples). Luckily we have been able to get 10 members back so far, so at least we are able to participate in war this week.
But the biggest loss is the members. We are not a top 10 guild (usually ranked 40-60), so while we have a number of active, chatty members, we also have a large # of members who play the game consistently, but don't communicate in chat. Many of these members woke up and assumed they were kicked. We may never get them back (for example, one new, strong level-150 member who was in the top 25 in the contest had already signed on with a new guild). And our other loss is the guild wall itself. We had spent the past 2 years on that refining and updating it. All that info is gone.
While I know Gree will not be able to go back and recreate our guild, placing all the former members back into it, having some resolution would be appreciated, plus the simple knowledge that this can never happen again. I don't wish this on anyone.