Ex not seeing his dd

I'll try and keep this short.
My ex and I have been split up now for a 18 months now.
He never sees his dd. In fact he has seen her a total of 5 times. The last time he saw her was 6 months ago. My dd skypes him twice a week. And she calls every night. Tho she doesn't really want to talk. She is 4 and I have started asking her if she was to speak to daddy. Half the time she now says no.
I am about to move in with my new partner. We have been together a year and he sees her every weekend. They have a really great bond.
My exs works 3 weekends of the month and 3 different jobs. He always has excuse why he can't see her.
I guess I am after some advice as to what to do. I am sick of pushing him to see her