Parents of children with complex special needs say they have been let down by Devon County Council.
Local authorities have a duty to provide a plan for children who need a lot of support, but inspectors found the council has been too slow in implementing changes.
14-year-old Matthew Harvey has just started at his fourth new school - all the others were unable to meet his needs.
Devon has a lack of special needs places for children in schools.
The council has written to thousands of parents to apologise for the previous failings, and bosses are promising improvements.
The council is £3.2million overspent on its special needs budget - next year's budget promises more than £11million for children's services.