Here's the thing. He needs to have physically gone to the territory at least once to be able to attack. He needs to have 1 troop in the territory. That's why he's attacking along a route, because he's driven it before.
He could be exploiting the flaw or just not have any idea that's not how the game is played.
We can't return troops or territories because the numbers are changing hands constantly. It would be fair to you but unfair to others.
As I said, contact us via
support@bnid.ca with your username and we'll compensate those affected in another way.