Sharepoint Designer workflow duplicate emails

Im using sharepoint designer to create a workflow with an infopath form that is held on my sharepoint form library. The approval process works correctly and the emails work properly but after having the appropriate person selected in a drop down, the email sends to that department head correctly, then they click the link and that department head approves, then it is sent to the materials manager to order and when she finilizes and sends off her approval so that it saves and is complete. It resends all the previous emails to everyone that was involved and creates duplicate emails for every email already sent. Any help would be appreciated this is not an out of the box workflow it is custom and microsoft helped but now they want to charge to help me fix the broken workflow they helped create .