(1) All fees for services are payable upon purchase or on receipt of a billing statement. The department may assess a collection fee of 18% annual percentage rate, or assess a minimum fee of $25, whichever is greater, for any payment amount not received on or before the last regular business day of each month. The department may require past due payment of fees prior to allowing additional purchases or providing additional services, such as inspections. The fees shall be as follows:

(a) pesticide study manuals: a maximum fee of $15 for each study manual; and

(b) pesticide applicator training courses:

(i) initial pesticide applicator training courses: a maximum fee of $75; and

(ii) fall pesticide core and category-specific training courses: a maximum fee of $30.