The Examiner is required to tell you which general areas you need to work on; however,he may not tell which specific questions you failed. If he did not do so, then you have grounds for complaint. Also, what did it say on the form FCL252 'Test and Examination - Notice of Failure' which the Examiner is obliged to give to you if you fail an exam?
The PPL confuser is of little use for the pre-flight planning section of the Navigation and Radio Aids exam.
If you fail the exam 3 times, you will be required to take a special CAA exam at Gatwick.