Hello, Recently I bought a dashcam from a seller which cost was $**.**. I received the...

Hello, Recently I bought a dashcam from a seller which cost was $**.**. I received the item ontime but it was totally useless since it has an issue with not taking sd card. Then I put a negative feedback to a particular seller as I lost from that deal. As he received the negative feedback he contacted me and beg me to revise the negative into positive feedback and he would resend the working item. And told me its not necessary to return the item back. So I trusted him and did as he told. First he told me that they can provide a shipping tracking number as they shipped the item. But ubtill now they didn't provide me an one. I'm so totally dispointed with that seller and the whole ebay because now its already more than one month after he promise. Other thing even I don't have an option to complain against that fraud seller. I can prove the whole incident through the messages between me and the seller.