DTs at independent school. Were told at end of last year name of form teacher. Found out 6 months into the new academic year that this teacher had in fact abandoned his form teacher duties and left them to the TA. When dh queried the situation the school initially denied this was going on, then admitted it and finally apologised. The head teacher claims he didn't know this was going on. The deputy head says he did know this was going on and tried to justify it. In the mean time concerns including concerns about bullying we have raised have been dealt with by different members of staff and in some case there has been no response. All this is documented. As various members of staff continued to defend this situation and dts were unhappy at school we moved them since it was clear the school was not providing adequate pastoral care. We are now being pursued for school fees having not given the required notice. We didn't give notice because we were increasingly concerned about the dts' happiness at the school and the school's ability to provide basic pastoral care. What is our position legally?