In the US I've found Charter, after 6 months, either A. Forgets I own my own modem and start to charge me a rental fee. Or B. Decided that my first 12 month dis

In the US I've found Charter, after 6 months, either A. Forgets I own my own modem and start to charge me a rental fee. Or B. Decided that my first 12 month discount is expired after 3-8 months. With Centurylink they seem to just add random services once a year, and I only catch it after 2-3 months of it being on my bill.