Dayananda,
If your client wants to send the goods back to its customer, then create a sales cycle.
At this stage, your company and returned the money, by creating a credit memo (RE).
So the entire sales cycle can be carried out, with last step of charging the customer for these goods.
One thing I find strange is so many times your client has cancelled the RE credit memo. Is the communication process between your client and its customer unclear and needs improvement?
TW