Ruling Question about preventing damage

[Matryoshka]

If I attack a Pokemon not knowing it has a pokebody that prevents damage done to it because of a certain effect, is the attack canceled and restated to a different Pokemon (Or use a different attack, etc.) or is my turn over (If the opponent would not allow to take back the attack)?

 

[DNA]

The attack will go through regardless of whether your opponent notices it or not. It's the player's responsibility to check for everything in play.
If a player has attacked and made a mistake in damage calculation (e.g. Resistance has been overlooked), the player may only take back the attack if the opponent allows them to do so.