Have you actually spoken to someone at ebay?
If you communicated via chat, you will probably have a record of that conversation?
If I were you, I'd go through chat again but keep going till you get to where you are speaking to a real person and request a call back or whatever.
Offer to show them a copy of the conversation where you were promised a refund of the final value fee and point out the dates.
You may get lucky with another ebay rep, they may honour the promise.
But I have my doubts because the problem here is you actually did sell the item through ebay, there was no fault at their end. The problem happened after the sale.
The problem is it was fragile and perhaps inadequately packed and was damaged in transit. So that's on you.
Even items that are packed with all the care in the world can sometimes get damaged in transit though.
You are not technically entitled to any refund from ebay, so if you do get one, count yourself very lucky.
You may have some recourse through the courier company, especially if they had any part of packing it, but you could check out that angle.
I suspect though you have lost the money, it is an expensive exercise & a shame this happened. Your best bet though in future is to sell with pick up or you may even be able to find specialised agents or auctioneers who sell these.
We used to sell on ebay many years ago but one thing we learnt was to steer clear of anything that could break, you really do need to take enormous care with anything like that.
