Here's what Apple says for the USA at Returns & Refunds - Shopping Help - Apple
(Tip: If you are not in the USA click on that link to see what it says for the country to which your account is set.)
"To return an item to Apple, sign in to your Order Listing page with your Apple Account and password.
After you sign in, you will see the items from your recent orders. Select an item to go to the order details page. From there, use the Start a Return link below your item and then click the Get Started button. On the next page, confirm the items from your order that you’d like to return and select the Initiate Your Return button.
Next, read the instructions and select the Print Return Label button to print your shipping and any required hazmat labels. If you’re shipping multiple boxes, use the Print Return Label button again to print new labels for each box. We recommend using the original packaging if you are returning a computer.
You can either schedule a pickup with the carrier or drop off the package at any of the carrier’s locations."
Alternatively:
"You can always return the item to any U.S. Apple Store. An Apple Specialist will assist you with your return. Your refund will be processed at that time. To locate an Apple Store in your area, please refer to the Apple Retail Store Locator. Please contact your Business Team to initiate a return for orders shipped directly to your business."