Activate iphone 4s bought from ebay?

I recently bought an iphone 4s on ebay and when I went to use it it said I needed the previous owners apple id. I contacted the seller asking him if he could take the phone off his account but he just told me that he bought the phone from someone else and has no way of getting in touch with the original seller. How can I make the phone usable? If I take it to the apple store will they fix it for me? If they won't fix it for is there anything I can do, maybe something in the phone I can change? There has to something I can do.

Ask the seller to help you with this. Apple won't help you as you're not the original owner of the phone. If you need help with getting the phone fixed, mail me for references.

Contact eBay buyer protection, then send the phone back for a refund. The seller "bagged" you, unless he stated the phone was unusable or as-is, get a refund quickly.

Used iPhone's are more trouble than the are worth, the phone might be stolen too.