Failed DSL installation, still no internet (DON'T MARK THIS SOLVED WHEN IT IS NOT SOLVED)

I made a post in the community 6 days ago to try and solve an issue of mine.
The issue of mine is very much NOT solved and has only gotten worse.
I will do a summary of the issues in chronological order, and if you wish to read the ORIGINAL post I made, it is here.

12/9/18 - I order "o2 DSL Free" and a router.
13/9/18 - I receive a confirmation-email of DSL instalment on 8/11/18.
13/9/18 - I receive a welcome email with information documents included.
14/9/18 - I receive a confirmation-email of DSL instalment on 2/10/18 (I requested this time instead of 8/11/18).
24/9/18 - Notification that hardware has been sent.
26/9/18 - Notification that hardware has been sent (I received it then too).
2/10/18 - A technician comes to my apartment, installs the DSL but says "something is wrong, I can only get 20Mbit instead of your ordered 50Mbit. this has to be fixed and someone will contact you later this week".
2/10/18 - Wifi works in the speed of 20Mbit.
3/10/18 - Wifi works in the speed of 20Mbit.
4/10/18 - Wifi works in the speed of 20Mbit in the morning, internet is completely offline in the afternoon and has been since.
4/10/18 - I receive an email from o2 saying that no Telekom technician visited my apartment and that I have to contact o2 within 10 days to book a new time for a technician, OR the contract will be terminated.
4/10/18 - I go to an o2 store to try and solve this. They give me a number to call. The number didn't work. I call support and tell them my issue. We book a new appointment on 9/10/18.
9/10/18 - No technician show up. I also have no confirmation email for the booking so I call the support again. I talk to the same person. They said "we only requested the appointment but it seems like they never confirmed it". I order a new appointment and it has been requested to be made "as soon as possible".
13/10/18 - I still have no email confirming ANY date. I contact o2 on facebook (because phone support didn't help me at all so far). They say I need to make a post in this forum.
12/10/18 - I contact Telekom in case they could help (because they are the ones installing the DSL. They couldn't help me because I'm not a Telekom customer, and they said o2 always wants to put the blame on anyone else.
13/10/18 - I make the original post "Failed DSL installation, still no internet".
15/10/18 - I let my friend contact o2 on support (because she speaks german and I thought maybe it's the english speaking support that just can't help me). They ask for my Kundennr. or Vertragsnr. I don't have this. The person said it should be in my contract I received in the post. I never received any post from o2, only email. The address to my apartment has however always been correct. In the end, this person didn't help us at all.
16/10/18 - o2_Lars replies to the post "Failed DSL installation, still no internet" and says that I just need to have "patience" and marks the post as "solved".
19/10/18 - I receive an email from o2 saying that no Telekom technician visited my apartment and that I have to contact o2 within 10 days to book a new time for a technician, or the contract will be terminated. I RECEIVE THIS EMAIL EVEN THOUGH I HAVE CONTACTED O2 MULTIPLE TIMES NOW AND NOTHING HAPPENS. Why should I continue to try and book a new time when you don't do anything anyways? Nothing happens and being in support for an hour to try to book a new time is a total waste of time when you as a company does nothing to help me.

If you wonder why I use a new account, it is because I can't log in to my old one for some reason and o2 doesn't let me reset the password. This is the only way for me to contact you.

Do NOT mark this issue as solved when you as a company has NOT solved anything for me. Patience won't help me, but you actually DOING YOUR JOB would.