Apple iPhone 13 Pro, No Signal

For the past 5 months, I've had a consistent signal problem with my phone. The signal keeps dropping, and I'm unable to use my phone for the majority of the day. They have been unable to find a solution despite taking my phone to the service center seven times. Despite the fact that I have provided video evidence of the problem, they claim they must see it in person to believe it. They advised me to change my operator, which I did, as well as my iCloud, but the problem persisted. I tried the same line and iCloud on various phones, but the signal only works on the phone in my hand. The service center has been unable to provide any viable solutions, leaving me with an inoperable phone. I am unpleased and would like my phone replaced. If a solution is not provided, my complaint will be escalated to the appropriate authorities.

My problem started with a similiar behaviour and unfortunately ı logged out to reset and ended up a with a phone unable to reactivate. Moreover, they claimed that unauthorized action which is under warranty. Please do not LOG off to reset as it will worsen your Case.