Was I scammed?

I found a ATv on craigslist, I then reached out to the seller, and they said that the ATV is posted on Ebay and gave me the link. I went and purchased the ATV using Ebay cards. The limit was $500 per card so I had to buy three to cover the amount of $1500. According to Ebay, Ebay holds the funds until I am satisfied with the product. Well the product never came so I call Ebay so I can start the process of getting my money back. When talking to the Ebay rep we had trouble finding any proof that performed a transaction. There was nothing concerning this transaction in my Purchase History. Apparently the invoice number that is generated once you use the Ebay cards is useless, because I asked if she could look up the transaction using it and she said no. The seller is not returning any emails, and there is no way to locate the transaction details.

Has anyone else had this issue, or have heard of this happening. I feel like the $1500 is gone and all I can do is chuck it up to is a learning experience, unfortunately as bad as it sucks I'm not sure what else to do. Any help or guidance would be much appreciated.