It's a one day ban. Random Selection or Auto as it's more commonly called does not make it 12 v 9. So you can't really deny the team stacking.
Your making snide comments about the teams(which btw I believe your team still won the map) does not equate to friendly banter.
I've executed exactly 3 commands against you. swap_team, kick and ban. I will tell you that, if you leave and come back in the same round the server auto-slays you, this is to prevent people who die quickly from re-trying and picking up their weapons and still playing the round, you can also be slapped for tk'in teammates.
Personally I don't have a problem with you. I have a problem with people who are only interested in their stats, always playing the same team, or just aren't interested in team play unless it's to their advantage and blatant team stacking.
I think you'll survive one day.