I did answer it, you simply failed to recognize it as such.
A school is an organization with a specific purpose. A teacher is an employee of that organization working there under a contract within a set of rules. The students are the beneficiaries of the services that organization offers. The teachers obligation is to provide those services as specified in their contract. Beyond that and other than the laws of the city and country they reside in, they are not obligated to provide any other service that is requested of them.
Demanding something that is beyond their obligations and expecting them to accomplish it unconditionally is an assholeish thing to do.
Ps: You presume too much. Just stuck to the written words and refrain the imagination that flows far beyond them. It will serve you better in the long run.