Freaking cc_sentinel banned me just because I was using labymod to get a better fps and I was good at pvp. I hate my life. PLUS I just got unbanned from a 30-day ban on Saturday. I was legit crying when I saw the ban.
-Tacosbefriends."We are now accepting reports from users using LabyMod, though we highly discourage it. LabyMod reports will be highly scrutinized to ensure the mod has not been used to produce false evidence. If a user creates a report using false evidence, the user will be banned depending on the severity of the report."
-Tacosbefriends.
That is probably why you were banned for the use of illegal clients, where Laby Mod is under that category.
You can talk with the Anti Cheat developer, @CrazymanJR about being denied.