Thanks digital, As far as understanding a bit better, does eBay employ people with or without brains, after all even those with a very limited IQ, should be able to work out that leaving feedback within minutes of making a purchase, is intended to do only one thing, that is to damage a sellers reputation, as such, such feedback should be immediately removed as soon as eBay is advised of the same.

That's just it... Often, particularly if you only email about the issue, you get an automated response based on keywords in the original message. That may or may not have been the case when you contacted eBay, but for feedback extortion to be verified, there would have to be communication between yourself and the buyer that a staff member could actively review. If they were unable to do that, I'm not confident they would have gone "but it does look like auction interference... " and take action. 

My own dealings with Live Help have often been frustrating, as it's quite difficult to get them to budge from a position where the buyer is in the right - I think they are quite restricted in how they are 'allowed' to assess and respond to the information given to them, so that while most others who had the capacity to critically assess the evidence and see that something is awry, they are bound to give some canned response based on certain things just like the email responses.