The only way that I see a package "not delivered" is if the buyer uses an address that is like an abandoned house, or a neighbors addy or a friends home or a business. The only way that I would give a refund or partial refund is if I screwed up on the address or if the contents were replaced by a love letter (Meaning I didn't package it well. Shipping within the usa and not sending a substance that has a heavy order should make it there with no issues. As long as the vendor follows all the rules. professional packaging, printed and professional looking labels.) In all my years of sending items through the mail (all pharms) I have not had one issue. If a buyer is going to use "fishy" addresses where there isn't a 100 percent chance that the buyer will be able to get a hold of the package, he/she should take 100 percent of the risk of it being delivered. Why should a vendor have to give up 50 percent or more of the funds when its totally out of the hands of the vendor. Its the buyers responsibility that the address that they use will work without any issues . The above only applies to USA to USA shipping. Customs is another issue. I hope I made sense.