I was told there was no guarantee there would be a job for me when I came back from maternity leave

I worked as a supervisor for a company and oversaw the running of two departments. I kept in touch all through my maternity leave and took 12 months off. Before returning I was told that I had to come back full time to do my job or there might be something they could find me but it would be a major demotion and most probably for minimum wage and there was no guarantee that there was a job at all. I had been there well over a decade. My daughter had just had an operation so there was no way I could go back full time so unfortunately I had to leave. This also happened to a number of colleagues, a couple of whom were made redundant after deciding to go back full time after finding out about my situation