Help - Child Maintenance Service

[unsi]

I currently pay child maintenance for my eldest son via Child Maintenance Service (CMS). In a nutshell, there was an issue with my ex husband saying I hadn't paid child maintenance (he lied stating that he hadn't received my cheques). I contacted CMS July 2016 and paid the full amount owing by bank card over the phone. I was informed by CMS manager that she would recalculate the payment schedule to take into account this payment. CMS had previously threatened to commence Deductions from Earnings but CMS manager told me that this would not happen as I had paid in full.

However, yesterday I received my payslip to find that £600 had been deducted from my wages. I immediately contacted CMS who told me that the Deductions from Earnings should not have occured and letter was sent to my employer in error. I was advised that CMS would contact my employer the next morning to request the money be transferred to my bank account immediately.

Today I have spoken to 2 CMS officers who state the case has been transferred to a Specialist Team and will be dealt with in due course. They refuse to liaise with my employer to rectify their mistake. They refused to transfer me to a senior manager.

I explained to CMS that to not be paid one third of my wages has put me in debt. I am the main breadwinner in my family (of 4) and have direct debits/standing orders due 1st Oct for mortgage, utility bills, etc. I have never been in debt and feel financially disadvantaged because of CMS mistake. I feel it is grossly negligent and incompetent, and cannot speak to anyone in authority to resolve this issue. Equally this is affecting me emotionally and I am extreemly stressed and worried about the outcome of this.
I have emailed my MP and fraud manager at work.
Any other ideas of what I can do?? Thanks.