My sister has been told by her employer of a few years that an attachment of earning has been put on her wages. After some investigation and a few phone calls found that it relates to joint job seekers allowance claim she had with her ex in 2012. Her apparently had £16,000 in a savings account that she had no knowledge of but as the main claimant she is liable for the full £7,500. She has been advised to get her ex to write a letter saying she didn't know about the money which he won't do because the money was his dads but his dad is on sickness benefit so put it in his sons name when he was first signed off. Is there anything else she can do? Thanks