We have added a setting that will allow you to display the amount a donor has given beyond the amount pledged. The Pledge Summary on the Giving tab shows the amount pledged, the amount given, and the balance. By default, the balance is displayed as $0 when the amount given is equal to or greater than the amount pledged.
You can now change the setting ShowNegativePledgeBalances to be True so that negative pledge balances are displayed.
This new setting is found on the Settings page, under the System tab and in the Contributions section.