I have a childcare problem, but school is insisting I come in full time

I started a new job recently as a teacher in secondary school. I went back to work with full-time childcare, but on my fifth day there, my childcare fell through and I was given five weeks’ notice by the childminder. I informed my employer straight away and resigned. The normal end date for a teacher would have been at the end of the term, but I asked for special consideration to be taken and for me to leave much earlier. They took five weeks to get back to me and have now said I have to come back after full time for the last half of term. I had managed to get two days childcare  and offered to stay two days a week until the end of term, but I physically cannot do the other three days in the week as I have no family or childcare options local to me that are available at short notice. What can I do? Can I just ring in each day and say I do not have childcare? They are fully aware of my situation and I have tried hard to get my baby minded, but could only manage two days and feel they have not even considered anything to help me. I am already having to give up my teaching career for this. Is there anything at all I can do?