Have you contacted eBay?

Items can be removed for various reasons,  but if a seller is removed from the site,  they have conducted some serious selling misdemenours, and to protect their members eBay remove them permanently from their site.

If you have contacted your payment provider first for a refund, well and good stick with that.  If not contact eBay first,  ( do not claim from both Companies at the same time ), for your refund as you cannot now claim from the seller.

@iauk_k7xskqc8s