Not sure if ebay can or will help but you can try. Click on "eBay Help", top right of page (or from My eBay pages it's "Help & Contact", top left). Scroll down to "Contact Us" and click on that. Select a topic, the nearest or any topic. On the next page, on the lefthand side you should get links to "Have us call you" and "Chat with us".
If not, if you paid with Paypal you can open a case with them (or with any other payment service you used). For Paypal open a case here:
https://www.paypal.com/uk/disputes/
And escalate it after 2 days and before 20 days.
