Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
How old are the children and when did the CSA first become involved?
Do you share their care exactly 50/50 and could you prove it?
But the CSA did not make a nil assessment?
Did you appeal that first assessment at all?
Under the newest rules where there is true 50/50 shared care then there should be a nil assessment - it is just that the CMS/CSA are very very bad at applying their own rules correctly.
Unless it is a nil assessment this time appeal it immediately - and then continue appealing as necessary - and always always deal with them in writing
Please ask if you need more details
What evidence do you have of the true position?
Are you aware that a phone call will cost more?
However the CMS are no more competent than the CSA
You may find this website useful
the fact that you in fact cannot apply for the Child Benefit further emphasises the nonsense that the statement is
When the CMS complete their assessment appeal it immediately - and in writing.
Never deal with the CSA/CMS by telephone