I returned to work in July 2017 after maternity leave for the end of summer term- A total of 3 days, I returned on my old contract. I then went part time from September 2017- 2.5 day (0.5). Over the summer I was paid on my old full time contract, the school are now telling me I have been overpaid as I started my part time hours when I returned in July???!!! I was under the impression I went back on my old contract, I also haven't signed a new contract for this year- where do I stand? I feel that this is very unfair as I returned on my old contract..