Bosch BCS1041WAC Unlimited 10 Return Issue

On June 26, 2025, I purchased a Bosch BCS1041WAC Unlimited 10 Cordless Upright Vacuum Cleaner from the Ege Shop store on the marketplace website Trendyol.com. I paid ₺17,907.00 for the product. My order was shipped and delivered to me on June 30, 2025. I opened the box to test the product. However, I was not satisfied with it. The battery life was not as good as advertised in the brochures and commercials, and after vacuuming, the device would release debris back through the head and pipe. I did not like the product and decided to return it, stating that I wanted to exercise my right of withdrawal, as I found better alternatives in the same price range. I created a return request via Trendyol.com and shipped the product back using the return code provided to me on July 4, 2025. On July 10, 2025, the seller, Ege Shop, called me from the number +90 533 682 75 66 and informed me that they had inspected the product. They admitted that the vacuum cleaner released debris back from the head and pipe, and that this was a known issue with these models, but said there was nothing they could do and that they would not accept the return. On July 11, 2025, Trendyol customer service contacted me and stated that the seller had refused the return, presenting a signed and stamped report from a Bosch service center claiming the product had no issues. I explained that I had exercised my unconditional right of withdrawal and that I did not want the product. I also mentioned that the seller did not inform me of this service report. Trendyol responded by suggesting I file a complaint with the consumer arbitration board, and the product was shipped back to me again, which I received on July 14, 2025. Upon opening the box again, I saw that the product was dirty inside and that the screen had 3–4 deep scratches on it. I contacted Trendyol again but received no resolution, and I could no longer reach the seller. There was no signed or stamped service report included in the box either. After the product was returned to me, I requested the invoice from the seller, who then sent me an invoice dated July 3, 2025. However, I had purchased the product on June 26, 2025. I am requesting that the product be accepted as a return and that the full purchase amount be refunded to me.