agrees with Jane ^

I am with the buyer too, Of course a toy that promises hours of fun at a party with, presumably, many children playing with it is not as described if it breaks after a couple of hours. I would have asked for a photo of the damage and once received I would have refunded in full without asking for return, after all you are not out what the buyer paid, just what the actual postage was plus a couple of bucks for the cheap toy.

that was one of my earlier thoughts.

atho your comments makes a lot of sense, the OP would then have to rely on good faith for the buyer will revise the FB, i think this is the OPs main concern, and not guaranteed as the buyer seems vindictive