TOPIC:

Simply... they failed with update and ruin your device. Should replace it on their cost. Either complete upgrade successfully according to tech note (obviously it either failed or not follow tech note completely) or replace device.
With device in this state you can not do anything.

The guy said that the update failed and due to the fact that they were closing and I couldnt let the car there, because I had to return to my city, they couldnt perform the update again. It is a time consuming procedure and for that it is preferable to let the car at the dealership and the technicians can have the whole day available. 
I hope that they could perform the update correctly the next time and have my car as it should be.

Well so;

I know a bit more about that. In dealership they brick my device on purpose (car was still under warranty) so they can change with a new one... I have good relationship with frontman in garage... 
Anyway, it was not hard to do that. Just one wrong step and device was dead. They even know which step to perform. 
Bottom line is: go back and if they accept to upgrade they accept the risk.

I have an appointment next week and I will leave the car at the dealership in order to fix it. From Rlink menu I can see that they changed the Boot Release of the programm. I had version 4711 and they installed version 5615. The guy I've speaked with, told me that he is certain they can fix it. For now, I can see the rear camera from the image adjustment menu and for now I park using this trick.

Hi

Good luck. They did not upgrade to SW v 7.x properly. If they can not upgrade successfully you will have half working device with no possibility to roll-back. 
 

I started looking for solutions if my devise have terminal problem. Does anyone has opinion about aftermarket screens? I've found a pretty good one, a bit pricy 650€, but I dont know if the parking sensors arround the car will work with an aftermarket devise