Why did the CSA get involved at all if they’re not going to take any money?

For the last 15 years myself and my fiancé have supported my daughter who was diagnosed with autism last year since pregnancy.

My ex has never paid a penny,I informed csa a little after she was born and my partner has provided for us ever since. Since then I’ve had the odd letter from csa until sept 2011 when suddenly I was getting letters galore saying I was owed thousands.

Convienatly I got married to my partner nov 2011 and now all I get are a letter once in a blue moon tellin me he doesn’t owe a penny what the hell is the point if no one bothers doing the proper research because now I’m married its my husbands responsibility to cAre for her lol.

Yet prior to our wedding my ex had every right to take me to court for access never happened never will guys not interested and why force it my little girl knows who her dad is and its not my ex that’s for sure.

My point being why tell me anything at all if ur not takin money from him to support his daughter yet I here of people going through hell being chased by the csa? Well is it just special people who get their lives wrecked by vicious exs or what? I’ve never had a proper answer from anyone.