I'm not quite sure what you're asking.
I am presuming that you received some jewellery that was not as described, and you opened a Not As Described case, and were instructed to send back the jewellery for a full refund. Is that correct?
If that's the case, I hope that you were successful in getting your refund, as that's far more important than the feedback issue.
Re feedback - if you mentioned a dispute/case/refund in the feedback comment, the feedback can be removed by eBay.