Further reading of the fine print in the Stagecoach document shows this:
218 Aberdeen – Westhill – Alford
This service which operates under contract to Aberdeenshire Council will replace Service X18 and will operate to a timetable specified by them. Certain trips will require a change of bus at Elrick. Within Aberdeen City, buses will observe limited Stops.
It would appear that our complaint is with the Council who at present subsidise the Alford to Westhill portion of the existing X18 route. It now looks like the Council are going to remove that subsidy so our complaint will be with them. Time to speak to our local councillors I think.