The guy sounds like a jerk... OK, more like an asshole... glad they were able to turn his hate into a good deed...
The daughters are correct to keep their distance from their vindictive father. You may want to take out your hate and anger on an ex-wife, but what did the kids do? He’s a creep, and if he is this resentful about supporting his children, they aren’t likely to see any further financial help from him, never mind mature emotional support and advice.