There are multiple ways to track the spending of Credits on the Account with the first being the allocations that you are able to set for individual Teams and Team Members.  You are able to set allocations of daily, weekly and monthly Credit allotments to individual Teams and Team members to allow you to track your Accounts Credits effectively.  

You can also generate a Report to see how Credits are being spent by clicking the "Manage" Button for the Account and then selecting the "Reports" Tab.  You will be able to select the Month and Year that you would like the Report generated for as well as what Team/s to include in the Report.  The Report will then be downloadable from the "Reports" Tab and will show you Credits spent, when they were spent and who spent them.