I can't contact the seller as they have said they would complain if i contacted them again.
It seems once i explained what they had done to the point they understood a positive comment is not positive feedback because of the -ve experience rating that all they wanted to do was disconnect.
I do not think they liked being show to be wrong when i sent the screen shot that showed the -ve rating after they told me the comment was positive.
The buyer asked "what do you want me to write".
Clearly no understanding of the difference between comment and rating and when given one they terminated the conversation.
It's not too bad, can't deny fate; and people are such that sooner or later some person is going to spoil a perfect record even if they had a positive experience.
Just very disappointed in eBay's response.
If there was any competitor to eBay i suspect eBay would see a noticeable exodus.

On the NSW Fair trading complaints register eBay constantly make it onto the list due to unhappy customers but given the huge number of transaction it is only foreseeable there will be the odd poor transaction and outcome.
https://www.fairtrading.nsw.gov.au/help-centre/online-tools/complaints-register