I've just had a message from a buyer to say that she didn't think the sizing I'd put was accurate (I said that a size L was size 'x', she thinks 'y'), but has decided to give the item away and only now has chosen to get back to me! She has ended her mail with the comment that she'll be more careful about bidding in future, which has mildly vexed me as I'm really careful with listing and have always refunded anyone who hasn't been happy.
I've said that I'm sorry that she didn't find the sizing accurate, and have offered a refund if she can return the item in its BN state to me, but apart from that what else can I do?!