Can I change feedback on ebay?

[beatie]

I bought something from ebay in October and never received the item. I opened a dispute with the seller and he promised to send me a refund (I paid through paypal) but that didn't arrive either.

Now, much to my annoyance, I realise that I gave him positive feedback, as part of a job lot of feedback I was giving!

Is there anyway to change this?

In a word, no. I don't know if you can post follow-up feed-back which could be more negative in tone. But I'm pretty sure you can't alter the feedback from positive to negative.