Well, in order to receive your credit, you do need to file a non-paying bidder alert. See link
. Make sure you stick to the eBay timeframes.
I would send the bidder an email defending (nicely) your side, and inform him/her that in order for you not to lose money on this deal, you have to file the NPB to get your credit from eBay. Let him/her know that you are more than willing to complete the deal quickly from here, or you need to do the NPB. Most buyers don't know that sellers have to pay
fees to sell things on eBay; they just think it's one big free swap meet.
Also, he/she seems concerned about negative feedback. You don't have to give a negative (or any feedback at all). The NPB alert will just be a strike against his internal
reputation with eBay (they get three strikes). You might also think about forwarding the link above to this bidder, just for his/her own information.
Hope that helps a bit! Good luck!