I am on a flexible contract which means I can be asked to work between the hours of 8am and 6pm. My supervisor agreed to me working 9.30-4.00 (I only work 30hrs) but if needed this could change, childcare allowing.Up til now this has worked really well with me being flexible on most occasions but having to say no - because I have limited childcare - on the odd occasion. My supervisor is now off long term sick and last week I was asked to change my shift to one which I couldn't cover for one day due to child are issues.This caused a major argument with the senior manager who told me today that as my supervisor is off, my hours will now return to 'shifts' and I will no longer have my agreed hours. I am ok with this but would like to know how I stand when they come back to me after the rota is published and tell me I must change my shift and I cannot get childcare. I feel as if I am being punished for saying no to one day!