Thanks for your responses. The buyer told me he couldn't find an option for damaged in transit, so he contacted ebay and they opened a case for him as item not received. I'm not sure why as obviously I'm not privy to the conversation he had with ebay directly.

In our messages over ebay, he's clearly explained the situation, with photos of the damaged packaging, but obviously no human at ebay has seen this as yet.

So the best thing I can do now is try and contact ebay over chat? I assume the buyer can't now change his reason by selecting anything on his account?