You used illegal software according to there terms of use (and I am sure you did, otherwise you wouldn't post this here), or someone hacked into your account and deleted all your weapons, according to there terms of use (that you agreed to) your account is your responsibility, therefor they are in there right.
They only thing you can do is request a timelog when the weapons where deleted, and if they where deleted by them, or yourself (yourself being someone who logged into your account).