I figured out quickly to buy sexed pullets. It's a lot easier to rehome one or two accidental roos than 7. I decided that if I was going to hatch my own birds, I had to be okay with eating any roosters I couldn't rehome. That's one of the challenging parts of chicken keeping.
If you feel bad about it, and think your collection method was to blame, you can offer to reimburse them for half of the roosters. Unfortunately you can't take them back due to biosecurity, but tell them they could sell them to someone else if they wanted to. I assume best case for straight...