CS and access aren't inter-related at all and you've been given some great advice

one thing i'll add though - if CSA are telling your friend she is entitled to CS, and she opts NOT to take it - she will not be meeting the maintenance action requirements for family tax benefit, and will lose about $103 a fortnight from her payment - so not only is she down the money he should legally be paying, but also money she could be getting from FAO. if the CSA collect the money, and he chooses not to pay, they will keep record of it, and can hunt him for arrears indefinitely...