Nope, that's not correct, you received an item broken, so not as described, therefore you are due everything you first paid for the item.
Business sellers do have the option to offer a partial refund if the item is returned back not in the same condition as sent out, but this has been abused here, as it arrived to you, with obvious inadequate packaging, resulting in a broken item.
Contact eBay Customer Services, though I do recommend waiting until tomorrow morning, contact first thing, when the lines open at 8 a.m. there's more chance of Dublin answering, explain what has happened here, you have not received the full refund, you are entitled to.
To Contact Customer Services it's a Live Chat, or you can select to speak and request a Call Back. Click on this link:
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
On the left sidebar you can see Have us Call you or Chat with Our Automated Assistant.
On weekdays lines open between 8 a.m. and 10 .m.
On weekends they open between 9 a.m. and 6 p.m.
