Hi, I've been reading a few threads and noticed that quite a few people have mentioned not being able to respond to negative feedback.
I have done it myself recently and it can be done! They just don't make it easy for you!
The link below shows you how to do it - if you're already logged in to eBay then clicking on the link on the page will take you directly to your feedback page! Hope this helps!
pages.ebay.co.uk/help/feedback/respond.html