Seller won't reply to request for new invoice.

[collectedbyclyde]

I recently won an item at auction that offered a box optionally if an additional shipping payment was made for it.  It said in the listing NOT to pay at the end of auction but to request invoice, which I did.  However, it has been 2 days and after several unanswered messages to the seller, ebay sent me an email saying the item is unpaid for and the seller could open an unpaid item claim.  Not that they had, but they could.  Are there risks to my account associated with this beyond losing the item?

What should I do?  Will I be able to leave negative feedback if I cancel the order or they cancel the order?  The seller has 100% feedback of 200+ so it seems unusual.  

If I waited could my account suffer negative consequences for non payment?  

Thanks, J