Odd, it seems to be fine now, it's been like this for the past month so it's likely to become slow again, so I better enjoy it while it lasts.
I'll give you the results anyhow.
EDIT: Internet is not the speed I was promised with, 100kb/s is still decent but the fact I'm paying for 100kb/s instead of 5mb/s is bullshit.
During the day downlaods are around 20 - 50kb/s.
First of all, you're confusing megaBYTES with megaBITS.
Megabits are often used to measure the internet speed you're getting by your ISPs. 1 megabit is equal to one eighth of a megabyte - exactly 125kilobytes/s.
Megabytes are used to measure what speed you're downloading/uploading at. 1 megabytes is equal to 8 megabits, or 1024kilobytes.
Could you clarify what you're downloading? It could be an issue on their side, or it could be an issue with Charter themselves. Charter has been known to throttle your internet speed if you're using it excessively, if you go over your monthly usage limit, or if a large amount of people are using Charter at the same time (to prevent other people from being slow).