A guy bought a brand new Sat Nav from me. Have sold a few of these and only have one left. The model he's sent back is even different to what the one left as I checked. It looks like he's returned an older model as the position of the stickers and the buttons are a completely different layout.
I posted the item at the start of the week. He's returned the item to me, but replaced the brand new with a broken and used model claiming that's what he received from me.
How do I proof that the item I sent was brand new as it's my word against his?