From personal experience with ebay phone agents, you could be in for a long and soul-destroying experience.

If you have the backbone and the fortitude for it, you could try to get them to see reason with regard to the buyer in question.

Possibly they will undertake to watch the pattern of feedback he/she is leaving, but that doesn't mean they will do anything about it.

From the 'horse's mouth' (ie an ebay phone agent) I've been told that ebay is primarily focused on retaining their buyers, clearly at the cost of their sellers' online trading experience.

Apparently on ebay buyers are more important than sellers.

Don't know quite how they work that one out ! Where would they be without us sellers !!!!

Its up to you to decide whether its worth the effort !