How do you review/change the feedback left for someone else when they dont leave feedback for you?

[c0mpute]

This has happened twice to me so far, I go buy something and the seller waits fr you to leave feedback first (even though you acted quickly with payments ect) before they leave you feedback. Though in some cases people dont to leave you feedback at all after you have purchased from them and ignore requests to do so.

So i was wondering if there is a way to change the feedback or another way to blackmark that person so it shows or warns others that if they buy off this person. that they might not get any feedback from them.. or to be able to atleast change the feedback to warn others... If not wouldit be worth suggesting the idea to eBay?

cheers