Party received item that was checked to be fully functional before being shipped. He emails back that item was not working and insisted on sending back. Item was advertised no returns, but I asked him to take to a shop to have it looked at and offered to assist in getting to work. He refused and began to send emails with profanity, extortion, and threats. Party returned item in which once I got back, observed that the party hooked up item wrong and ruined item.