I'm getting to the MP stage of a CSA complaint, and have been hunting for information on the internet, through various forums and finding bits and bobs here and there. Thought I would put them in a post, as some of them I didn't even know existed, and I'm 10 years into a CSA claim.
This is a very helpful sheet from Gingerbread, about some of the terms and info CSA could use. I would have really appreciated this 2 years ago, as it backed up some of what I was arguing and CSA were telling me they could do nothing about!
This is a Subject Access Request form for the CSA. It costs £10, but they have to send you all information they have on you from their files. Phone calls, letters sent out, file notes, etc.
The complaints form for the CSA. The only time I have received payments is when I have complained, so do it regularly if they aren't following through. However, even they admit you are likely to just get a phone call and apology. Worth keeping up though!
Find your local MP here to start the complaints process with them. Some are apparently better than others though.
Not many links, but thought they may be helpful to someone else. If anyone has any advice about involving MPs, or CSA advice, please post! I'm sorry this doesn't have any advice about CMS, hopefully it will all still be relevant for them too.