I'm not convinced the black one is male... but it could be.
Where did you get these chicks? Was there a sexing guarantee? Hatcheries will usually give you a refund or credit if the sexing was less than 90% accurate. If you got them from an individual, I'd strongly recommend letting them know that their "sexing technique" is either completely bogus or backwards. There are a lot of old wives methods that people are completely sold on. Honestly, though, if it was that easy to sex chicks, nobody would end up with cockerels who didn't want them.
Where did you get these chicks? Was there a sexing guarantee? Hatcheries will usually give you a refund or credit if the sexing was less than 90% accurate. If you got them from an individual, I'd strongly recommend letting them know that their "sexing technique" is either completely bogus or backwards. There are a lot of old wives methods that people are completely sold on. Honestly, though, if it was that easy to sex chicks, nobody would end up with cockerels who didn't want them.