If I remember correctly, when entering your password for deletion it will log you out and begin deletion. If you log back in on that world, it cancels it. I would suggest trying that again in-game, to see if it works.
Bear in mind that deleting your account only deletes it on the specific world that you select deletion.. so if you're trying to delete on multiple worlds/delete your entire account, you may be getting the correct response but not the response you were expecting.
If, after further attempts, it is still not working as it should, please read
this thread, try the recommend fixes there and, if the problem persists, edit your thread to include the correct format.