I sold an item last week, the buyer sent a friend to collect it and about 24 hours later sent a message saying she was very unhappy with the condition and it was not worth what she had paid. I offered a refund if she returned it (it's a vintage item) but she said it wasn't worth her time or money to return it and was quite rude in her message saying it was "knackered" asking for some recompense. I said i could give her £5 or she could return it. Her last message was "just send the £5".
I can't leave her bad feedback and don't want her to leave me bad feedback either but am quite cross! Is there anything I can do?