I had a 12mth contract for a part time position of 20hrs a week. The terms of the position changed and they wanted someone fulltime, the position was to be advertised and I could apply if I wanted to. Due to health issues I could not work full time so I did not apply. I was given a months notice and managed to find another position so I gave them notice of one week. Due to a health problem I was unable to start the new position but may be able to start at a later date if there is a position. My problem is that when I asked my previous employer for a separation certificate they put my reason for leaving was due to my having another job. If they had not changed the position to a fulltime position I would still be there so my reason for leaving was due to them changing the position but they wont say that on a separation certificate and this will leave me unable to claim centrelink according to them I left voluntarily. What can I do about this