Changed your mind
Change of heart, wrong size, bent tube out of the box — all of it goes through the store that sold the piece. Their return window and their process apply, and both are printed on your order page, which is where the return starts.
Keep the box until the rack is standing and loaded. A frame that goes back travels in the packaging it came in, and flat steel without its box rarely survives the trip in a state anyone can resell.
The money moves back the same road it came, on the store’s clock. If a listing arrived not matching what this site told you, we also want to hear about it — not to route the return, but to fix the page.