Regulation 6(5) of the Civil Aviation Regulations 1991 provides as follows:-
Any person who has failed any test or examination which he is required to pass before he is granted or may exercise the privileges of a personnel licence may within 14 days of being notified of his failure request that the Authority determine whether the test or examination was properly conducted.
Isn't this the answer to the exam question? You have an avenue of appeal laid down in the regulations. If enough of you exercise you right to appeal maybe they will think again. The have to give you a fair hearing on your appeal = alot of time and effort!
Good luck - hope you're within the 14days!