Ebay sends you an email stating that the listing has
been removed. In that email there are links to click on if
- you have not yet paid (you need do nothing in this case)
- you have paid for the item but not received it.
In this case you would click on the "I have already
paid for the item" link and go from there. Paypal will
return your payment to you.
As far as old sales go. You should be able to see that
page and image in your cache, or using google's cache.
Furthermore. Depending on the reason that the lisiting
was removed - when you bought the item, you received an
email from ebay with a) the item number b) the sellers
name etc. In this case you can apply direct to Paypal
for a refund, in the resolution centre.
I also once received such a "ebay listing removed"
message - someone was selling DVDs of current
audiobooks of my favourite author, pirated copies,
basically. I had already paid but contacted the seller
via his paypal address and he didn't only send me the
DVD I paid for, but two others for free with old
Sherlock Holmes radio episodes on it.
So don't despair - there are lots of options open to you.