I waited for a very long time to get an appointment with Guidion and finally yesterday someone came. Apparently the internet room in the ground level where the fiber connection is going to the house is not connected to my apartment, you would have to pull a cable through a tube in the wall. I was thinking that the technician would do that but he did just connect the fibre optic in the ground level and left. He suggested that I can buy a long lan cable and put that under my door through the hallway/staircase and then under the door of the internet room. I actually then did that after he was gone because I need the internet desperately and this was the only thing that I could do. But this is no save installation and I will have to remove the cable soon. I called the customer service multiple times and the two suggestions that I got were: 1. pull the cable through the wall yourself (its 3 floors and around corners I have no idea how to do that) and 2. contact Guidion and make a new appointment and pay them (I would have to spend a lot of extra money, wait for ages for Guidion to give me an appointment, have no internet in the meantime and I cant even reach them by phone since there is always more than 1h que). 

I am now really confused since I made a contract for t-mobile to provide me internet, but I am now responsible to assure that it is actually technically possible by spending money? The other tenants of the apartment told me, their provider just did it free of charge without a problem. I even called other providers and they all told me that they would do it free of charge to assure that my apartment is connected.