All the staff commissions are present in Analytics → Staff Commission Report.
To delete the amount added earlier you need to find the employee and the amount.
Then you need to open it and press the delete icon.
This way you can also modify the amount if some mistake has been made while calculations.
To do that choose the amount and press the modify icon.
There is a common mistake. Users tend to believe that if they modify the price and the amount of goods/services in the ticket that the system would modify the commissions in the reports automatically. This is not true. You have to remember that the system would automatically add a % to the commission of an employee according to the ticket as soon as the proper status is assigned. What is the right thing to do:

1. Delete the false amount in the report
2. Open the ticket and modify the status "In progress"
3. Modify goods or services
4. Chose the status that triggers the commission.