A: Pullet bin is not 100% guaranteed to be female. It is in the 90ish% range.
B: Having a Cockerel is not a bad thing at all. Unless your geographical local prohibits you. If that is the case, he could be raised until he matures and can be sold for the handsome price of chicken feed for the rest of your stock.
We breed a lot. We hatch many males. We have zero problems turning them into some sort of profit.
Just interact with it a bunch if you plan to keep it. The more you visit him and interact, the more human friendly he will become. Most people with problem Roo's just chuck them feed and go back in the house. If he is use to your presence, he won't feel you are a threat or invading his territory. The territory belongs to the both of you, once he matures at the ripe age of 6ish months or more. That's when the crowing starts and the hormonal changes begin.
Good luck on what ever you decide to do.