DSL Aktivierung Terming keeps being cancelled

Hello, hope you can help me here.

I moved to a new address in mid-November. Since then I've been trying to organize the Techniker to come and activate my connection.

The first Termin I got was 28.11. No one came. Later when I called I was told they didn't have the information how long cable I'll need (!?).

I got a new appointment for 02.01.I event travelled back to Berlin for it. No one came.

When I called them I was told the line is occupied by the last tenants. Nobody had mentioned it earlier. So lots of calls/messages with my landlord later, I got a new appointment for 29.01. They sent the info to me over email, and it was in my o2 online account. Yesterday when I went to check it, it had just disappeared (exactly like last time) with no info there or on my email.

This morning I received an e-mail: "Willkommen bei o2 DSL..." with a new Termin on 11.02. I do not understand 😞 There is no way to confirm this from my side either but looks like if I don't they will just delete the Termin again. What can I do??

It has become very frustrating as I work remotely and home is supposed to be my office. But it's been 3 months without wifi. Especially as I'm paying for it.

Any advice super appreciated !