Grrrr I hate eBay for drama's like this!!!
I purchased items from a seller, paid as soon as the items ended, and never got them! The seller then went on to call me a liar and a thief and went as far as to call me and my DH schizophrenic! They hurled tonnes of abuse at us via email and messages on eBay... I contacted eBay who told me to forward the emails on to them with all the headers attached, but when I went to do that, they were denied by eBay because they were too long and had the headers attached!!! So this woman has got away with her continued harassment of me and my DH (yep, she still harasses us 3 months after the initial issues)
I tell you... it has made me VERY wary of buying now as this seller had a fairly high rating but had some recent bad feedback left for them too. I actually got my money back from that annoying seller thankfully.

I hope you get everything sorted out. And I would go ahead and leave very negative feedback. I thought eBay was meant to be cracking down on people charging too much for postage? What a joke huh?