Trendyol Holding My Money Hostage for Defective Product I Refused

I bought a rechargeable power bank from Trendyol, but it was malfunctioning. I returned it, but the merchant refused. So I mailed it back; this time, the vendor refused it because the package had been opened. To avoid being treated unfairly, I sent the thing back again, only to have it returned. Since the merchandise never arrived, I notified Trendyol, who claimed it had been received. However, I disputed, claiming that I had not received it. Despite their promise of a response within three business days, five days elapsed with Trendyol claiming that the merchandise was with the seller. At this point, I refused to accept the merchandise, citing its wear and tear as well as its defective nature, and requested a refund. They agreed. However, after receiving a message, I learned that the product had been rejected and would be returned to me in its original condition. I restated my unwillingness to accept the product, and they responded by stating that the seller has the right to reject the product on the second return. I questioned this judgment because it appeared like they were going to sell the damaged product for which I had paid. I am speaking up here, requesting the restoration of my money, claiming that my rights have been infringed, and insisting that my cash not be withheld.