I wanted his eBay gift codes. I needed them since I wanted an expensive gift for the GF. Asked for 2 x $500 codes, the deal was $700. I said sure, and we negotiated until we agreed that I send $20, then he sends both codes, then I send $680.
Make fun of me, I can't even believe I put $20 down the drain just like that. Oh well, his stupid scamming paki ass can eat for a year now.
In the future when making payments, always use an address you control and can sign messages from. Anyone can post a link showing a "proof" of payment from a web service. Using your own wallet removes all doubt.