User Activity

A buyer left me negative feedback by mistake. She emailed me to explain that it was meant for a different seller! I completed a feedback review request which the buyer completed. The negative feedback has not been removed by ebay! What do I do next? ...
An item was purchased from me in August and the sale went through smoothly. Now I have received an email from eBay notifying me that the buyer did not bid on the item and they are returning my selling fees etc. What is happening?