http://resolutioncenter.ebay.ca/
Send the buyer a Request for a Mutual Cancellation.
Usually the buyer would like to have the refund at the same time.
When she agrees (or if she ignores it) your FVF will be refunded. Agreement makes the refud immediate(ish) while ignoring the request takes, I think, seven days to complete and then you get your refund.
The reason if one is asked is 'buyer changed mind'. Otherwise you get a Defect.