Without going into too much detail I'm sure this was fine when it left us, and the damage she's claiming couldn't realistically have occured during transit. But now she's demanding a refund, and says "it wouldn't be worth you paying for return postage on a useless item so I've disposed of it for you".
As it happens the postage was less than the item sold for, but not by much. But why make that assumption? I guess I have no choice but to accept it, but I have a nasty feeling I'm being scammed and the buyer (new buyer, not much feedback yet) has found a way of getting something for nothing.