Isn’t it like being a radio station with 5,000 listeners but claiming to have 50,000 listeners and charging advertisers on the basis of having 50,000 listeners?
Not quite, because in this case the 50,000 listeners do exist. It's just that 45,000 of them are shills paid by the radio station. But if the advertising contracts didn't exclude for that, then there's no grounds to complain.