Switch to AT&T Uverse. It's the best thing I've got.
Also I've been in your situation like 50 times.
We would have no internet for weeks.
Then one time when we didn't have it for like 3 weeks...they gave us 1 year free of 5Mbps(instead of the 3mb/s we were paying for)
It was good but it still sucked.
So we switched to uverse. It is the best thing I've ever had.
The only time it's gone offline and no internet was for 3 hours and that was in the beginning when they were having trouble setting it up. But it's all good now and never goes offline. And if it does, they fix it within hours.
Also the 5Mb/s is cheaper than Charter's 3Mb/s and it also includes TV with where you can record things like TiVo.
Just get it now.