Hi @LK8, sorry to hear about this.
I am afraid that it is hard for me to detect from a distance what the root cause of this behaviour is. I believe that the best thing to do in this situation is to get in contact with your local support team, they should be able to direct you to an authorized service center or arrange for the phone to be sent there for repair.
If you have any questions regarding the service such as service routines, warranty and consumer laws, these kind of questions are best answered by your local support team as well as they vary depending on where you are situated.
I hope that helped a little bit on the way!
