Amazon Lost the SteelSeries Headset I Sent to Warranty, I Need a Refund

I purchased a SteelSeries headset from Amazon on October 30, 2023, and sent it for warranty on July 2, 2024, because it was broken. On July 3, 2024, they returned the headset with a document required for a refund. I contacted Amazon and informed them that I had sent the product and the document and requested a refund. Initially, I emailed a photo of the document and then sent the product to the Amazon warehouse on July 4, 2024. On July 10, 2024, I was informed that the product did not meet the necessary conditions for a refund and, therefore, they would not process the refund. Despite having included the document from the warranty service inside the package, it seems they lost it. I called customer service, and they told me that since the document was missing from the package, they would not process the refund and would return the product to me. On July 12, they began the process of returning the product, but today, July 29, there is still no news about the product or the refund. During these 17 days, I have contacted Amazon customer service four times, but they have done nothing but cause me inconvenience. I have also attached the document related to the refund. It's truly disappointing to see such a large company create this kind of mess.