I would very much appreciate some assistance here since my internet is practically unusable.

I have been a customer with Telekom for about a month now, and so far it has been a giant mistake. My internet goes down for multiple hours, approximately every second day. For example, it went down yesterday morning for about 2 hours, then again in the evening for about 3 hours, and it has been down today (saturday) since about 7 am and it is 10:20 am now. I try everything to bring it back (firmware updates, restarting the router etc.), but nothing works and it just comes back at random. 

When it does work, there is about a 50% chance that I am getting 1/10 the speed I pay for (yes I know the difference between bits and bites).

As someone who works from home, this is completely unacceptable and I question what I am paying for. 

When the worker came to install my internet initially, he had doubts whether my router (provided by Telekom) was even functioning, but after some time (longer than the worker expected), it lit up, and so he left it as-is.

Please help me here.

Best regards,