Ebay allow to buy "return labels" without tracking number. If the seller decides to say "I did not get the item" that's it, you don't get the money back because according to "Ebay-Service" the "responsibility for giving back the item lies on the buyer"... And you cannot prove you sent it back, because there is no tracking number. Then, why did you let your customers to buy "return labels without tracking number" in the first place??!!