I've never had to disconnect. Once the discount has expired, I just go online and check the prices for changing my internet speed. Most of the time there's a discounted one (with a contract agreement of course). But I've been switching back and forth between different speeds for years and saved a lot of money that way. Also buy your own modem/router instead of paying rental fees for their equipment.

Careful, sometimes they'll come out just to pull your plug from a concentrator when you disconnect, or it just happens when they're hooking up a new customer and yours gets unplugged to make room. But then they turn around and charge like $50 just to come out and plug that back in for a new install. That can be the entire install, you can bring your own modem and have everything fine inside, but some yahoo charges $50 to come out and plug some coax into a concentrator in a box 20 ft from your house that they unplugged for free last week.

With Time Warner you don't even have to do that you can just call up and ask, they'll probably give you the discount. They absolutely do not care.