Hi, I'm new to the game so I still have the original shield active with 10 hours left. However I've been attacked twice already, 18 hours and 2 hours ago.
The original shield was for 24 hours, have you played longer than that? If so, it's likely that you were attacked and given another shield.
It is highly unlikely someone has attacked you while under a shield. If you should send a screen shot of your defence log that would be very helpful in tracking down the problem.
this happens to me too - after i've been defeated, i get a shield (the game gives me a shield, i don't buy it) and then when i say i'd like to have revenge, the game says "you'll lose your shield", but then i get attacked anyway. so it's confusing to me what is happening.
1st, keep in mind that the shield you are given when you are defeated has a max life of 12 hours. 2nd, you should never go to attack any human players while under a shield unless you're prepared to lose it, because you will lose it.