Xiaomi 15 IMEI Clone Issue After Purchase From n11

I purchased a Xiaomi 15 mobile phone from the n11 website on 14.08.2025. After inserting my SIM card, on the 5th day, I received an official BTK message stating that the device was cloned. Thus, I found out that the phone sent to me was not a proper, legally registered device. After this message, I contacted the seller/n11, and I was directed to the technical service. At the technical service, I was told that they could only activate the phone to work with a single line registered in my name. Moreover, they stated that they would do this only if I signed a declaration they prepared, in which I undertake not to file any complaint about this issue in the future. I find it unacceptable that a cloned device is sold and then a solution is offered only on the condition that I waive my right to complain. I do not accept signing any such commitment. I request a trouble-free, brand-new, completely original, and legally registered Xiaomi 15 device to be provided to me as a replacement for the cloned phone sold to me, and I ask for this process to be completed urgently and without imposing any additional cost or commitment on me.