WebPT Ideas and Discovery

I would like therabill to reflect a negative balance when a patient paid a copay lets say at time of service 2/2/19 and then on 4/2/19 the insurance processed that date of service and paid it in full. Turns out the patient didn't owe a copay. Right now we are unable to apply the patient's paid copay. I would like to apply the copay to the DOS and therbill show a negative balance or patient refund due. Then I would like therabill to have a report of patient refunds due. The current aging patient balance negative balance report is very confusing.