In case the challenge you are talking about is this one:
Then you did indeed draw one game, but you lost the other - draw gives 0 points, a win 1 point, so the other clan won the challenge 1 - 0. Your clan only gets points if you win, or if you draw the entire challenge. If the total score for the challenge is in favour of your opponent, then your opponent gets ALL the points, regardless of whether you got some points in a game inside the challenge. For example, if you had drawn both games, or your opponent had won one and you had won the other, then the score for that challenge would have been 0 - 0 or 1 - 1, and then the challenge would have been drawn.