I think your ladder is broken

Likely the reason you lost is because you lagged out, and dropped from the game.  Rather than just dropping you back to the menu, it replaces all of your opponents with bots.  Likely, the actual game went on with the three other players actually playing the game, and your team lost.  I'm assuming that since your name starts with KOREA, you're in Korea, which means you could have a pretty high ping just from being physically far away, and getting dropped.  Further, a lot of games don't get recorded.  It's something they're working on, but sometimes they just don't record.

I didn't lag out. NO, i'm korean living in the US. I've never had any lag/disconect issues in this game unless someone has a simspeed of 0 or negative and it dropped at the beginning of the game.

The person who was on my team said the same thing happened. He saw only himself in the game. I saw only myself in the game.

Well then maybe everyone dropped into their own games and only one of them counted.  But I can almost guarantee that the game that counted was one that was played to its conclusion and recorded.  It's kind of a tough problem to deal with, since you can't just count all of the games, and you can't just not count the games, because then people could drop to avoid getting a losing record.  You're right, it's a problem that should be looked at, but it's just how the game works at the moment.  The problem with the "win" being recorded as a "loss" has to do with connectivity, I can almost guarantee it, not the ladder.

yeah ladder is broken, I have same stats as you and im no 3000+, actually had a post about this if you check:

http://forums.demigodthegame.com/351229

But Frogboy said they are looking into it (well was quite pissed I keep nagging about it :D)