iPhone 16 Shows "No Service" After 1 Week—Media Markt and Apple Ignore My Issue

I purchased an iPhone 16 from Media Markt on November 9, 2024. After just one week of use, the phone began displaying a "No Service" error. When I contacted Apple support, they confirmed that the issue was hardware-related, not software. I took the device to Media Markt at Gaziantep Forum AVM, and they sent it for servicing.

The phone was returned to me on November 21, 2024, with a software update, but within 30 minutes, the "No Service" error appeared again. I sent the phone back for servicing, requesting a replacement or refund, but it was once again returned after a software update, without resolving the issue. This 20-day-old device has already been to service three times, yet the problem persists.

I invested a significant amount of money into this phone and expect a resolution. Media Markt says they will follow Apple's service decision, while Apple claims they cannot intervene since Media Markt is the seller. I’ve been left without a functioning phone for over 20 days due to this back-and-forth. I demand an immediate replacement for this defective device.