Customer Service can be challenging

I messed up on my inventory system and a customer ordered a Chinese Girl's Dress I did not have. So I went to my supplier to try to get one. They did not have it at their store, but they said they would have it at their warehouse. So I finally got to their warehouse, and surprise, they don't have it. I did get some items for another customer! So I went back to their store in downtown and started going store to store looking for it. I finally found one and I paid retail for it, since my goal is a happy customer. So I get back, ready to ship it, and when I test the zipper... Any guesses? Yes, it broke. So I eMailed the customer asking what to do. I should have tested it in the store. Another learning experience!