Didn't receive your item

[efforeye]

I ordered 3 items from a seller. Two of them arrived within a few days. The third item never came. I was told by the seller that I had to wait 30 days before I could file a claim to make sure the item didn't come seperately. It never came and he is saying it isn't his problem! I am trying to file a claim, but PayPal tells me I have to use eBay and eBay tells me the item was delivered already! What do I do?