As a rule.
So everytime you have a problem you better make sure to call the right firm, because the other won´t help you, EVEN THOUGH IT´S VIRTUALLY THE SAME COMPANY and even though some problems affect both parts.
But that´s not all. Telekom has the habit of charging too much and has a lousy attitude about it. I talked to the people in the service department on various occasions (after waiting around 30-45 minutes for a human to pick up the receiver each time) and it was never fun - although I saved a lot of money with these calls.
For about 6 months they kept sending me reminder letters every week after the monthly bill had arrived and charged me 1 € for each. I called them and reminded them that they had a written permission to take from my account whatever amount of money they pleased whenever they pleased and asked them to stop sending me (and charging me for) the reminder letters. After 6 months a service lady advised me to write another permission and send it in, which I did. The reminders were finally history.
After using their internet service for about 6 months I got a bill of roughly 200 €. Since I´d just paid their last bill which I´d received only a few day before (with a much lesser amount) I called them asking what this one was about. The woman on the phone couldn´t tell and advised me to ignore it, she´d take a look into the matter and write me a letter of explanation.
The letter never came, but - of course - the infamous reminder did.
I called again and the man on the other end informed me that I hadn´t paid the basic fee for my internet access. O.o
Me: "Eh, what? I always paid whatever you charged me."
He: "Yeah, it seems that we didn´t charge you the basic fee for 6 months. Our mistake, I guess."
(I checked the previous bills and found it was true, they had indeed forgotten the basic fee.)
Me: "Okay, whatever. I want to pay in instalments."
He: "That´s not possible."
Me: "Why the hell not?"
He: "We don´t offer that service in cases like this."
Me: "But it´s an awful lot of money and anyway it was your company´s fault."
He: "I´m sorry, but we don´t offer this service. You´ll have to pay the whole amount at once."
Me: "I´d like to file a complaint about this. Please tell me the name of the person in charge of this department."
Well, he did and I wrote a very polite, but firm letter, stating that while I understood that mistakes happened I found it extremely irritating to have to pay for the company´s mistakes. A few days later the reminder letter for the 200 €-bill arrived, accompanied by another letter...from the boss´s office. It basically said "Sorry for the inconvenience, but please pay the amount in full. In exchange you won´t have to pay your basic fee for the next 6 months".
I did what they wanted, realizing that most people would have paid right away, without complaining, hence throwing good money out of the window.
For a while almost everything worked fine.
However, when I decided to change providers and gave notice they sent me another bill of 300 € without stating what it was for. I called again.
Me: "This bill came out of the blue. What´s the amount for?"
He: "I can´t really tell."
Me: "I´m not paying that if you don´t tell me what it is for."
He: "I´m sure everything is in order."
Me: "Well, if you´re so sure tell me what it is for!"
He: "I don´t know. Probably fees from 3 years ago."
Me: "WHAT?! And you´re charging me NOW?!"
He: "I´m not sure. I can´t see it in the system."
I refused to pay this bill and after 2 months another letter arrived, stating that 'out of the pure goodness of their hearts' Telekom had decided that I wouldn´t have to pay these 300 € (not their exact words, of course, but the gist). Gee, thanks.
All that plus the few times I had problems with the internet and was forced to call their incompetent service line makes me want to puke every time I see a Telekom commercial. I´ll never go back to that company EVER.
As an amusing addition the guy from Arcor (the provider I´m using now) didn´t cancel the DSL line (which he´d promised me he would do) and Telekom charged me for another month. I went to the guy complaining about this and he said: "I´m sorry, there has been a misunderstanding in another department, just give me the Telekom bill and we´ll pay it."
I probably gawked at him for more than 10 seconds, before stammering: "...YOU made a mistake and YOU are going to pay for it?!"
Took me like half an hour to digest this totally weird feeling of being a cherished customer...
Germany isn´t exactly famous for the way customers are treated (more 'infamous', if you ask most people), but this went beyond everything that had happened to me (so far)...