I know they mean well but I am starting to get frustrated ...

It is clear that they will not offer any extra acceleration or enrichment in maths until some 'authority figure' (that has to be dutch and from their official circles) tell them to do so,

They have requested the help of a special committee and for that they have to fill in a questionnaire explaining what the problem is. They gave us the form, ok good, but it is clear that they do not fully believe us. They say for example 'in the classroom X does this, but at home the parents say X does different'.

Fortunately we can participate in the next meeting of this committee (usually this is not the case), but we have to plan our strategy very careful.