@ProlongedAffair it's about time you took some responsibility for this mess that you have created and stop blaming everyone else. CMS aren't at fault or responsible. You are 100%.
You said why would you take legal advice from MN, but you've not taken legal advice at all have you? Probably because deep down you knew what what 99% of posters were telling you, including myself was correct.
You were told repeatedly in your very first thread that for 50/50 no child maintenance was due, if I recall you ended that by saying you had sought advice and we're not going to claim because as everyone told you it was due on 50/50.
You then made a 2nd thread where you had in fact claimed CMS and were shocked because your ex put a claim in for one of the CB. You have been told over and over that he would win that that CMS base their decision on what you tell them not evidence. You were told that he would likely put in a claim for CMS and will win it just like he will win in court and that you would have to pay back every single penny you received under your false claim.
Throughout this you have obsessed over the kids being registered to your address with GP and Dentist etc. They don’t allow registration at more than 1 address, just because ex let it be your address didn't and doesn't mean you do more.
Your ex was paying you a generous sum of money despite not needing to, he LET you claim both CB even though he was entitled to claim 1 of those.
You've admitted that you earn well and you don't need extra from your ex to live that it would be good for savings or holidays. Your greed and bitterness towards your ex has led you to where you are.
Maybe start putting the interest of your children first instead of trying to line your pockets from a man that owes you nothing just because he earns more. It isn't his job or obligation to fund your lifestyle.
You need to take a long hard look at yourself and how you live your life and stop blaming everyone else for the choices you made.