Faulty phone

Good day, I am very disappointed and unhappy with my device I upgraded on Friday 16th June 2023, I took the double deal Redmi note 12 pro phones, the one phone works perfectly fine, but the other phone has a problem when the screen locks, I can't open the phone again so I have to switch it on and enter my SIM pin, I communicated this with the consultant that assisted me, he tried to assist me over WhatsApp, I even factory reset it with no success, he than advise me to go into the store again(Menlyn) to get assisted by a technician, the technician checked the phone and said I should go to the repair shop which is a floor above them, I went there, the lady that I spoke to did not even bother to look at the phone and see if they can do something about it, she just said the phone needs to be booked in, I refused to do that because I feel this is a new phone and if there is a problem they should replace the phone, what ever the fault is, it's a factory/manufacturing fault why should I go up and down and struggle with a phone that I am paying for, now I have to wait 7 days for them to see what is wrong with the phone and me be without a phone for so long is not going to work, I need a phone for my work purposes and I have small kids that is going to school so I cannot be without a phone.

I have to go up and down, that is costing me for a manufacturing fault. I am really not happy with this.