I have had flexible working since 2016 this was done through a statutory request which was accepted and was made permanent, I have worked the same 2 days (backshift)since it was agreed as my mother cares for my daughter while I work as she works mornings .my employer has now tried to change my shifts without consulting me. Their are other employees who have flexible and they are still being allowed to continue with their set days even though their kids are older than mine, my boss says i shouldn't need it anymore as my child is due to go to high school and I can leave her in the house for 12 hours on her own. What are my rights ?