If you have used Retroactive Billing on a pledge once then you would not be able to use it again on that same pledge. We suggest you consider opening a new pledge for the new charge. 

However, we found that if a Retro Bill charge was rejected then it should be retried so long as the reject count on the pledge is still below your threshold for Maximum_Number_of_Charge_Rejections. This was not happening in prior versions of Team Approach and is fixed in Team Approach version 5.0.20.