Hi all,   I want to sell some ducks but want to do it like a classified as I wish to discuss with the buyer where they will be keeping the ducks, what sexes they are wanting and so forth. If I make it a Buy Now (like i just did) and then someone buys say 3 and pays $60 via Ping but they want certain sex or colour that I havent got or they have inappropriate housing how can I "undo" the sale? Hope this makes sense? Rachel