You don't need to speak to anybody from Ebay.
Open a return case. Use the reason 'not as described' or 'items incomplete/missing'.
This will alert the seller to the issue.
They can send a label so you can return what you did receive and get a full refund or they could offer to send the missing items.
Open a return request
To request a return, select the item you want to send back from your recent purchases above, or use the button below. You can also start a return request from your Purchases in My eBay.
Start a return - opens in new window or tab
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)