After 6 months the basic driving school fee?

Hello folks,

I started my driver's license six months ago. I wasn't allowed to attend the practice for three months because I wasn't vaccinated and many of the driving instructors there were sick. I called there recently, and the instructor told me I had to pay half the basic fee to stay enrolled at the school. But there's nothing about it in my training contract. Is it normal for them to require this?