Certain Ebay members do not comprehend the feedback system and use it an negative way.
Beware of those who punish you for giving them neutral feedback by giving negative in return.
Even if sadly Ebay feels they cannot intervene.
You may encounter rude emails and innapropriate comments should you enquire about why you received such comments.Do not be alarmed.
Just remember not to buy from them again and do not worry too much about you new feedback score, which has probably decreased significantly in one go.
Remember that you were using the feedback system correctly and gave information for future buyers.
Consider whether you do want to mutually withdraw feedback when offered : balance the feeling of wanting your feedback score to be higher again and the position of 'feedback blackmail' this seller has put you in.
Good Luck fellow ebayers
(Should you wish to identify the source of this inspiration (without whom this would not be possible) feel free to click on my profile)