A Amazon marketplace product I ordered was wrong. I ordered a memory module and got the wrong one. After checkingy order I saw that I ordered the right one. No problem, I thought. Filled a return form, entered "wrong product" as reason, send it back.
The marketplace reseller denied my refund because he claims I swapped the product. I escalated the issue to the Amazon support. They told my that this decision is final and I can nothing do about it. I let my lawyer send them a letter. Only then Amazon gave me my money back.
This if the story how Amazon lost me as a long time customer because of poor and stubborn support over a 23€ product.