On ebay I sold a Monitor 18.5" LCD for $30 plus $10 shipping. Well I had no idea what media mail was. It was cheap and it said educational purpose and Hard drives and etc. So I thought I could ship a monitor. Well the post office made the person who bought the item pay $8 more to pick it up. He is demanding that I send $8 or he will file it as mail fraud can he do this?