My ex stopped paying CM because contact was denied. What happened was he e-mailed out of the blue demanding contact the next day and every alternate Sunday. I replied our son had just left on an expedition with the school and I thought he already arrangements with a recoding studio for some of the Sundays. Threats of court action ensued and CM stopped.
That might have been understandable if our son was younger but he was 18, contact had never been a problem and our son had been making arrangements directly with his dad since he was 16! The CSA caseworker just doubled up with laughter at the thought of me (I'm 5'4") forcing a strapping 6'+ 18 year old man into his car and making him drive himself to contact.
1) "I have spent enough on you and your kids (my kids!!) over the years" (obviously forgetting the I too worked like a dog to provide for the kids and also carried him while he took a career break!).
2) "You want to carry on a WAG lifestyle but I'm not funding it anymore" (believe me having to ask for every penny I needed was not a WAG lifestyle!).
3) "My fiance (before they married)and the child we are expecting are now my priority and I cannot buy things for the new addition if I am paying for my other 2 children" (This was actually on his form E!).
4) "I cannot pay CM because I am paying off joint debts" (there are / were no joint debts - when I asked him what he was talking about he said his credit cards which I had no access to and with which he bought all his gadgets!).