I sold an electronic exercise device on the 23rd of November, it was in the original box with all the attachments, item had been used a handful of times, it was given to me by my neighbour to sell (used my account to sell as I have a lot of good feedback) i check and double check all items before I wrap and post.
I received a message this morning from the buyer saying that the plug was missing from the box and he wants a refund, he said it was a Christmas present for his 'missus' she opened it yesterday morning and there was no plug. He then told me that he was 'pissed off and I sell crap' and has opened a case.
I messaged him a few times assuring him that I was 100% sure that all the items were in the box, he then got ruder so I haven't answered any more messages.
Where do I stand on this? I know for a fact that nothing was missing.