OH pays through csa to his ex for one of his kids. After some enquiring regarding his childs status he has received a letter saying due to...(the reason)... the payments should have ended 5 months ago. OH has been (and still is) paying his ex every week. How does he get back all the money he has over paid? And will his ex be done for fraud? Surely she will have been claiming child benefit all this time too? It is her not informing csa of any changes that has caused the overpayments. Anyone in a similar situation?