My personal thoughts:
If you haven't ridden in 4 years, then don't waste your money.
Go back and do the m1 exit course, and learn the basics, or give up riding as you did for the 4 years.
Some people get out to the course or the test and don't know any of the basics of riding on the street.
If that's the case then you're wasting your, the other student's, and the instructors time.
Some people have towed their bikes less than 50 km to a course, which says something about their own opinion of their skill set.
Most courses I've seen don't just teach to the test, they also tweak your street riding skills.
Some people are good riders, but don't do as well as they could in traffic or street situations.
A coach following behind you, watching and correcting, can make a difference.
If the course isn't or hasn't done that, then they're missing out on adding value to your riding, and you should let them know.
I'm that good a rider, so I like to try and improve every year by taking at least one course. Even the pros have people watch and coach them.
The idea is to make it a life long learning experience, that's also interesting and fun.