Ive sold an item on ebay and sent it out to the buyer recorded delivery all in its lovely presentation box fully working and packed well. she has the item left great feedback and then week later says doesnt work , her husband has tampered with the screws on it and also she has ripped and damaged all the presentation box so its not worth anything now she has sent it back to me for full refund and ive taken pictures of it and she has wrecked it what do i do she wants to take it up with dispute. please help its a £70 item!