btc price is very volatile
your 120$ can be 98$ tomorrow
he only has to refund you the amount in BTC not in USD
i think you seem a little bit confused with the report
I sold him something but he did not send the money which was 120$.i sent him accounts not BTC. He was supposed to send BTC. I did not mention any BTC amount ofcourse sellers usually dont mention that when they are dealing via chat and just accept the current BTC rate. But when he sent it i saw the amount he sent was 104$ and the btc amount is going in his favour. The amount is 106$ now. I dont care about the amount which is tomorrow or yesterday i only care about the amount he sent at that moment which was 104$ .