I'd like to file a formal complaint.

I've waited TWO weeks now for someone to hook up my internet. I work remotely and depend on having Internet without data caps as my work involves large datasets and I'm required to be on-call (so tethering or working in a free Wi-Fi spot will not work for me).

The technician was scheduled to come today:

1) He showed up and asked for access to the basement

2) The door was already opened for him by the Hausmeister - he then shut the door, locking it

3) I had to call the Hausmeister (who lives across the street) - to unlock at. The technician said that 2 minutes was too long - and that he was going to leave.  At this point, two minutes had passed, the Hausmeister arrived and greeted the technician. The technician still decided to leave.

He told me I needed to make ANOTHER appointment. It is absolutely absurd how I was treated - and on top of that he was extremely rude. This is affecting my personal income.

Where can I file a formal complaint?