Are the pullets you bought are from a hatchery were only girls are born?
This is possible (abortion at day 11) and done in large hatcheries for laying hybrids for the egg industry, so they can sell the eggs with the label ‘ no chicks dead ‘ or ‘no cockerel dead’.
Some countries in the EU such as Luxembourg, France and Germany already have a national ban on the killing of day-old chicks for the egg industry. The European Commission now wants all EU countries to follow their example.
But as far as I know this abortion method is not common practice in hatcheries for back yard chickens. If the hatchery has no label with ‘ no cockerel dead ‘ you should realise that your response was to let someone else kill 25 - 30 male chicks for you.
Btw, I do love it that you do your best for the all the chickens you have and are hatched in your office and grow up in your backyard (or was it the other way around

).