Ekua, if you used paypal, couldn't you get a refund... then again, the refund process is difficult through paypal. I had an issue on ebay, involved paypal in the dispute and lost. Either way, I, too, am quite hesitant these days in swapping or selling.
I don't know but I don't think people are as honest as they should be, or have good intentions when swapping/selling. From now on, I think I will just purchase from the vendor. It's safer.