Question: Where do you get disconnected? Is it when you log in on the Nexon site? Or is it after you actually start the game? Also, remember that Nexon North America's Vindictus can only be played in the US and Canada. They have IP blocks for anywhere else.
If you disconnect after starting the game, that's a known issue. If you keep trying, you might get in. To be honest, I can't really recommend playing Vindictus until Nexon fixes latency issues. It's okay to have lag early on, but once you get a ways into the third boat, lag will really mess you up since Laan relies on carefully timed dodges, Fiona relies on carefully timed defending and counters, and Evie just relies on not getting hit at all. :V