I sold some Disney collectables in the last month and everyone made quick payments except one person. She has promised payment on three occasions and finally (its been 2 weeks) I'm a little miffed. I know if I relist the item it will sell but still I have paid ebay the fees from it being won.
She only has 13 feedbacks but they are positive and I hate to leave negative feedback but then I hate to think of someone else not getting paid! If the person has a problem and had explained it then it would be different but just promising payment over and over??????
She only has 13 feedbacks but they are positive and I hate to leave negative feedback but then I hate to think of someone else not getting paid! If the person has a problem and had explained it then it would be different but just promising payment over and over??????

The last time I looked, the idiot had a -3 feedback, so he's probably been kicked off ebay since then.
Worked out great for me. 

I do not know if leaving a negative feedback will work against you, but there were some good suggestions like blocking the person.