I grew up with an absent dad, too. I know my mother struggled with this as well.
She never said anything to him. She said she finally realized that she couldn't force him to be a good father, no matter what she said. My father wasn't connected to us, and she couldn't make him be.
Personally, I think it was better that way. I learned exactly who he was, and was able to make my peace with it (with therapy).
Now, as an adult, the relationship I have with my father is one of MY choosing. I see/speak to him when I want to.
I think if he'd been forced to visit us/call us it would have been worse. We would have known that he really didn't want us around and that would have hurt more, I think.
Rejection sucks---but forcing someone to interact with you hurts, too.
Does that make sense??