What would our next best option be to help my daughter get what she deserves?

My daughters father has not made effort to see her in years. Poked at the situation every once in a while . Like every 6 months to a year . His typical plan of attack is to say he wants a schedule then he never comes around. Gets my daughters hopes up and then something usually comes up. In the past 6 years he has not had her overnight once and he has picked her up maybe 3 times to hang out. Each time pushed by me. But every time he says it’s my fault he doesn’t see her. He hasnt even make plans to see her on bday for years. He has three more children now with his wife and my daughter says “ it’s not fair to them that they don’t get to know their sister!” She’s been in therapy for this 6 years and has an amazing head on her shoulders . Great student. Very responsible girl. Her father is often late or absent with child support and he refuses to pay for medical treatment because he didn’t authorize. His wife is a lawyer and they are doing very well. His child support is very minimal and hasn’t been increased for years though his income has. I don’t feel my daughter should have such a limited life because of this. She is a worth more than this.