Make sure the order is confirmed; unconfirmed orders are to be canceled.
Most problems with member refunds are timing issues:
1. Too soon: the transaction has not yet settled in A.net. Confirmed orders are bundled and sent to A.net at the end of the business day, so wait to issue the refund the next day.
2. Too late: the originating order you are issuing to issue the refund is too old. You will either need to issue the refund directly in A.net and/or write a check.
3. Wrong cc: the member has updated/changed their payment method since the order was placed.
4. An expired/canceled credit card will not accept refunds.