You have so much to learn.
There are many fathers out there who pay child support without fail. However, when it comes to spending time with their child, the mom has all the say. It doesn't matter what is in the divorce decree. Mom will simply "forget" to tell Dad that she won't be home Saturday morning for him to pick up the kids. Or Mom will tell the kids that they can't do something special this weekend because "It's Dads weekend and you have to go with him."
All the mother has to do is make one phone call to the court/police, and they jump on her word without even checking to see if the story is true or not. I knew a guy who had the police pick him up at work so many times for failing to pay child support that it got to the point where he had to carry cancelled checks with him to prove it. It didn't matter though. The police still had to pick him up, take him to jail, process him and he spent the night until the next morning to appear before the judge. Then he would present his side of the story, the judge would release him and set a court date. He had to pay for an attorney just to show up in court to prive he wasn't behind in his child support. But because this was a child support case, the mom didn't have to show up; the prosecutor would be there, see the proof and the case would be thrown out of court. But he was arrested at work, forced to spend the night in jail, pay for an attorney, then miss another day of work to be in court.
He might have been proven right and the case thrown out, but to what expense?
The stories go on and on.