I've not had success with removing negative feedback.. just need to ride it out for 12 months until it drops off.. and it does.. remember feedback is subjective and in my experience handled well by replying to show how you have dealt with the situation. If all other feedback is AOK then potential customers will pinpoint that particular buyer as shifty, not you. Its a terrible feeling though.. sorry its happened 😞 Crime stoppers is a good place to register stolen goods. They perform data checks with second hand dealers however I'm not sure whether they monitor eCommerce platforms like GUMTREE? Be great if they did...