I Faced Screen Issues Twice with Samsung Z Flip Repair

I bought the Samsung Z Flip model in November 2021, and although it was never dropped or damaged, a line appeared along the fold. Within a month, the touchscreen began to fail in the folded section, affecting half the screen, and eventually the entire screen stopped working. When I bought the phone, it was advertised as being able to withstand 200,000 folds and highly resistant to impact, and I was told it would be easily replaced if there were any issues—none of which turned out to be true. When I sent it to the service center, they claimed it was user error and charged nearly ₺11,000 for a screen replacement, which was done in March 2024. However, by December 2024, the same folding issue began again, and by June 2025, the touch function had completely failed. I sent the phone back with the invoice from the previous repair, but this time they asked for ₺13,000 for another screen replacement. I objected, arguing that the warranty should still be valid since the repair was done at the authorized service center. Customer service responded that service-installed parts only carry a 6-month warranty, which they claimed was stated on the invoice—yet this detail was nowhere to be found. When I challenged this and asked for a voice recording proving that they had informed me, they later admitted that this was not told verbally and is only mentioned if specifically asked. It's absurd that a global brand like Samsung does not transparently disclose warranty terms for replaced parts, neither on their website, nor in service, nor on the invoice. I feel cheated—two top-tier phones, thousands of liras, and months of time and frustration wasted. Samsung has proven to be a huge disappointment in terms of product reliability, service, and customer support.