These comments are from my own experience in dealing with CSA. They notoriously get it wrong, fail to follow their own policies (or the legislation), and apply a different standard depending on whether you are male or female. I've had to take them to the Administrative Appeals Tribunal three time so far because of their failure to get their decisions right in the most basic ways. In each case I've raised formal objection with them and they have failed to revise the errors.
The first time, they ignored a clear requirement in the legislation. We had protracted arguments about requirement, and the CSA kept quoting their guidelines at me - despite them not being relevant. I took them to the Social Security Appeals Tribunal (before it was incorporated with the AAT), and CSA's legal department made submissions with agreed with my arguments completely.
The second time, they ignored inconsistencies in the other parent's statements - despite having them in writing. They preferred the view which gave the other parent the best outcome; disregarding my submissions, the last ones by the other parent (which agreed with mine) and the representations of the other parent's partner. Once again, I brought this to their attention via objection and it was disregarded. I took the matter to the AAT and they ruled in my favour.
I can't comment on the third one, as it is ongoing. All I will say is that the errors are even more basic than the above two.
I don't want to blow my own horn about the above, but rather point out that (at least from what I've seen) CSA can and do make horrendous decisions; and refuse to back down from them. Check what you've received and their reasoning very carefully or, better yet, get a lawyer to do it for you. Don't take as gospel what they tell you. Check the guide (
Using the Child Support Guide | Child Support Guide and the legislation (
CHILD SUPPORT (ASSESSMENT) ACT 1989 and
CHILD SUPPORT (REGISTRATION AND COLLECTION) ACT 1988). The guide should point you to the correct provisions.