Can you let us know how you perform the relist? Did you click on the relist link or you perform a change in the quantity of the item?
This will help us understand better the case and reproduce the situation by looking at the detail activity log.
The generic log did indicate that 2 credits were added back during July 18, 2012 6:45 pm EDT. We will assign a ticket to investigate on this matter and read through each of the event for this incident.
We will be adding back two credits for you for this incident.