QI forgot to pay the Audit/course enrollment fees.

Payments before or after the specified period will not be accepted under any circumstances (including cases where the payment was attempted within the deadline, but not completed). Non-payment will result in exclusion from the course and may lead to a drop in your priority ranking if selected for enrollment by lottery next time you register for courses.
Even if you are not allowed to take a course due to non-payment, you will not have the opportunity to register for additional courses.