I just want my ex to support his children

I have had terrible trouble with CSA sorting out a calculation since Jan 2011. I spoke to someone yesterday who kept calling me my ex partners previous partners name and informed me that she had been receiving all the payments and my sons nothing., also that they had received the information twice but not actioned it.

They also confirmed they can just access tax credits information and us it, it annoys me when for 2 children my ex has paid £18 in a year yet lives in a big 4 bedroom house, has numerous nights out a week and lives a life of luxury.

I don’t want him to be on the poverty line I just want some support to raise our children.  I was told yesterday that I would have a call back but still nothing.  It’s a joke.