Did the buyer open a case, or did you just refund him?
I assume there was no tracking either.
Refunds are sent back to the method of funding used. So if the buyer paid through PP with a credit card, it will go back to the card, but can take several business days, depending on the bank. Since you are not privy to the buyers banking, you cannot track the refund, but he will have received a message from Ebay that you have refunded, so there's not much more you can do.
A lot of your items would fit into the green domestic tracked letter for about $3.00. Might be worth getting a few of those, upping the postage and then at least you have tracking for peace of mind.
