There is always a chance of troll-style result, normally you should have ~1 per season. This is 100% true for the real football, by the way.
If such thing can make you upset, if you think that the strongest team should always be victorious, if you can't withstand a random defeat, then your decision is right -- don't play another season.
But if you are still here, how many SoT your team made? And what was the score?