Selling already sold stuff

Bought motorbike from private seller on gumtree. Owner notified me that bike is standing at dealership and that the dealership have been notified that the bike was sold on the Wednesday by the owner. I got a call from the one owner round about 15h00 on the Friday to confirm the collection and payment the Saturday morning. To my surprise i got a call back round about 17h00 to tell me the bike was sold unfortunately. At first i though she called the wrong person because i know it was \sold\" to ME.! Do not believe it when they say first come first serve. These people don't work like that and very *********."