As an ex-instructor I could rant for about 5 pages on here, but take it from me - it doesn't matter. You may have failed legitimately or you may have been shafted, just take the test again.
My wife and I were both instructors, and we got out of the business because we felt we were constantly urinating contrary to the prevailing airflow. Everybody thinks that we take driving seriously but fact is that most of us don't, if we did there would be a lot less carnage on the roads. The governments that are supposed to look out for us don't really care, nor do some of the alleged safety organisations that act more in their own interests. The problem is systemic and it will probably not change in our lifetimes.
Do you know how long it takes to become a hair stylist in this province? It's a full community college course that takes about 9 or 10 months. A driving instructor course? About 5 or 6 weeks. We have both taught on those courses, and most of the time was spent trying to teach the applicants how to drive properly. Why not make it tougher? Because they would simply go to another training centre with lower standards. The trouble is that being a driving instructor is an entry level job - you get off the plane from who-knows-where or drop out of high school and drift for a few years looking for employment, and if the local convenience store isn't hiring you become a driving instructor.
Recent studies have shown that people who learn from a driving school are no better at driving than someone who learns from a family member, the only advantage you gain is that instructors have a second brake to keep you out of trouble, assuming the clown in the right seat knows how to do their job.
Last, look around you at all the twits you have to dodge on the road, and I can guarantee you that the vast majority of them passed a test and have a license. So what does it mean? Next to nothing. As long as you are a safe considerate driver I really don't care if you've paid the authorities a fee to get a plastic card with your picture on it. If you forget it's in your other pants does that suddenly diminish your capability? Nope.
Just get on with it, and once you pass take it very carefully, because no matter who taught you there is a lot more to learn, and you'll be doing it on
your own with a few frayed nerves to show for it.
And sign your donor card.