Fuckin' morons on eBay...

Sold my W530 on eBay, CLEARLY wrote "Ships to USA only." Some Sri Lankan dude bought it, then asked me to pay for shipping. I said "It costs $70 to ship via USPS, can you pay me?" So he did. I sent it out, only a few days later it returned to my house cause USPS doesn't allow lithium ion batteries to be shipped internationally. So I told him I'll give him a full refund, he said "No, ship via UPS. It costs $240. I'll pay you $50 since I paid you $70 and we'll split the shipping." Uh, no? Why should I pay for shipping?