A very influential male cousin of mine, went to hell and back to keep in touch on a regular basis with his two young daughters, when his then wife walked away with someone else. He spent thousands of pounds going to court for years and even though he won his case, his ex refused to let him see them or communicate in any way. She then spent all her time brainwashing the girls into believing their dad was bad.
Funny thing was, it was her who went off with another lady's husband in the first place. Not because my cousin treated her badly, but the other guy was richer. The worst thing he has had to face was this narcissistic mother insisting on giving the elder daughter away on her recent marriage instead of him. He got a very cool invite, but felt too humiliated to attend. It has wrecked his life not being able to see his girls while they were growing up. The good news is the younger daughter now an adult with a mind of her own has returned to him.
But they will never get back the years they missed together.
So to advise people to fight through the courts is a total waste of time and money and only upsets the children who don't understand any of it. The mothers always win in the end. Not to mention the solicitors who take on the cases, probably knowing the outcome at the start.