If the plunder attempt was repelled by the Galata Tower, it will actually show up under the Battle Filter or it might be the Social Interaction Filter (which I find highly amusing on a personal level).
I have to say that when you consider that they changed something about the timers on attack/plunder and when an attacker can still plunder (the 24-hour restriction applying to ability to attack being counted from the time of the plunder, not the first attack) I think we should be able to filter it so we can see when we can expect another attack and react accordingly. It just seems that the 'fix' on that created more of an imbalance than it fixed. (I don't personally worry about attacks/plunders but I can see how it might have rattled my cage once upon a time and do the same for other players).