Actually, if you are providing a service, those using the service have a basic right to it.
As Fred Reed said, the only way you can teach a child for 12 years and they still can’t read Is if you are actively preventing them from learning to read. Either that or they are munching way too much lead paint or drinking way too much water from the Flint municipal water supply.
I'll be sure and tell the Electric, Telephone, Gas and Cable TV companies when they send me a bill...............