Chaqa, as much as it's convenient for you and your team to cloud things, let's make sure the situation is known. Two things have happened:
1) In a tournament announced explicitly as anonymous in order to prevent metagaming, the tournament director's team led the way in attacking one of its opponents because of their team membership rather than the position on the board. This is not something that we merely suspect, because there is public press in a FP game in which one of the other players directly admits it.
2) When our team accepted that this was now considered legitimate in the tournament and decided we would do the same at our next opportunity, we were told that it was now against the rules and would lead to sanctions if we attacked the TD's team in the final.
Of course as an experienced player I understand that given the opportunity, players will gang up on a perceived stronger player/team. The tournament rules explicitly stated that this was to be avoided if possible via anonymity, though, and we attempted to respect that, like most teams did. So it was certainly...unpleasant to see that it was the tournament director leading the way in breaking this implicit agreement. But we can accept that it was only an implicit agreement and difficult to enforce.
What's absolutely ridiculous, then, is being told that rules now change if we decide to retaliate. Yes, there's a long tradition of attacking perceived strength in Diplomacy, but it's always also fair game for strong players to retaliate selectively in order to discourage this. The idea that it's okay for the TD's team to break the implicit agreement because it benefits them but it's not okay for somebody else to do it in a way that hurts the TD's team is patently ridiculous and turns this tournament into a farce.
You asked for a solution? I think there are two reasonable solutions, either of which could work:
1) Enforce the anonymity that was promised. Disqualify, at a minimum, the teams that explicitly used team information as part of convincing others to ally with them. One player even admitted in public press that their choices were knowingly poor for their own power. I do not know whether this includes the TD's team, because it has yet to be revealed which player was publicly misbehaving in Group A's FP1.
2) Accept that this can't really be an anonymous tournament and allow our team to retaliate in the final, as turnabout is fair play. Allow us to play under the same rules that the TD's team has been allowed to play under and that other teams in our groups have been allowed to play under, because that's a minimum requirement for fairness. This might mean that we make choices that are knowingly bad for our own powers in some of these games, but it's already been established that this is okay in the 2016 World Cup, so we deserve the right to make that decision for ourselves.
Either of those would be an acceptable solution. Any "solution" in which the TD is allowed to benefit from breaking anonymity and then conveniently change the rules so his team can't be harmed by it is unacceptable and should be seen as unacceptable by the entire community.