Separation order

[clolee]

Finally split from partner nearly four years ago after a turbulent 17 years. We initially had a joint mortgage and he moved out back in 2006. I gained a separation order which he signed. I paid him £15000 up front and another £15000 was meant to be paid to him when daughter left education. At the same time the mortgage was transferred solely to me (the £15000 had to go onto the new mortgage, and the deeds were transferred to me also). The only reason I paid first amount straight away was due to his bullying. Two years later he moved back in after we had got back together but never had his name on any bills apart from council tax. In the separation order it clearly states that we would 'continue to live separately and apart from each other'. I have just received a solicitors letter with regards to my ex and the money he says he is still owed. He clearly hasn't got a copy of the separation order as all dates and figures are wrong. I would like to know if he is actually due any money as I would have thought the contract we had became null and void when he moved back in for those two years. Any ideas anyone??