I have a Chinese friend who suffered exactly the same fate 2 years ago in s Shanghai. On top of the fees for the test etc. there is a “tax” that is paid to the instructors as a bribe and the going rate at the time was 200 RMB.
Don’t pay it you fail, Pay it you pass irregardless of your driving ability.
The first time he refused to pay it and was failed, the second time he paid and passed.
This blatantly suns up how the country operates and the mentality of people.