One of the things that I try to avoid when debugging a problem, especially one to which I don't have real insight into, is assuming that because two things co-occur, one must be the cause for the other. More often than not, the two things are actually both caused by a third, unseen event. However, when my Roadrunner email (which I rarely use) suddenly started telling me "account disabled" immediately after I had a new digital phone line installed, it seemed to be too coincidental.

The real fun was trying to figure out how to get Time Warner to listen to me without having to sit in a long tech support queue and argue with some level 1 tech about why it wasn't working as they walk me through unplugging and replugging my cable modem, forcing me to narrate my pretend actions so that they will finally transfer me to the next level.
I have learned that you will always get more leeway if you buy something, or ask about available services and their prices when you actually need tech support. This works for two reasons, in my experience:

1. They have a more customer-service oriented mindset, and so they want to make you happy.
2. They tend to be less technical, or at least have fewer notions about being a technical person and so they will listen when you offer up a problem diagnosis.

I remembered that I had asked for voicemail on the line but they did not add it for whatever reason, and this provides a clear "in" to the sales line. I try the tech line first just to see if I can quickly resolve it, but the wait is > 45 minutes. I then try the sales line; I get a person right away and I explain that I want to add VM. No problem, they can add that for me.

Me: Oh, and BTW, my email account stopped working right after the phone was installed.

Sales Guy: Oh really, let me look at that...yeah it looks like it got confused here. Let me fix that for you.

Me: (astonished silence)...uh, thanks

10 minutes later my VM was active, and my email was back online. So anyway, the moral of the story is: to get good tech support, tell them that you want to buy something.