Of course? So what? Many of those children will not have children of their own, so that puts them in a different class than their parents. Which is why that is different then going to school.
My parents never got time off to just take care of me. I was on my own. Do I get a refund or a credit? Maybe a vacation voucher?
Can life not be better for us or our children than for our parents? This kind of thinking keeps everyone down.
That's a separate argument from claiming that everyone was once a child so they must have benefited from something similar.
Even further, just because you benefited indirectly through a parent, someone who doesn't have children is still receiving less benefit than someone with children. They are getting the benefit twice. Whereas a childless person gets it once and indirectly.
They should file for FMLA benefits retroactively. Ask them to look into it. Also, who fed you?