If you see duplicates in your contacts that means that you have added your users as contacts and you will need to merge the contact with the proper user, so that the information for commissions and additional information in the transaction and reports reflects the proper information.
Select the required contact and click Delete button.
If there are any payments or transactions assigned to these contacts, the system will ask you to select another contact or user to whom you want all information to be transferred. Once you select the proper user, the system will merge all entries.